HGRC(5)

📦

version 7.2.4 · 8 versions

7.2.4 · alpine 3.24, arch rolling, fedora 44, nixpkgs unstable (latest)
7.0.1 · opensuse-leap 16.0
6.1.4 · epel 9
6.8.1 · epel 10
6.1.1 · ubuntu jammy
7.1.1 · fedora 43, nixos 26.05
6.7.2 · ubuntu noble
6.3.2 · debian bookworm

, in alpine 3.24, arch rolling, fedora 44, nixpkgs unstable

💅 HGRC — the Mercurial config files manual page (yes bestie, `hgrc(5)`, we're doing this)

Okay so, real talk: this is the Mercurial Manual page for hgrc, aka the configuration files for Mercurial. It's long, it's iconic, and we're gonna get through it together. Grab a strawberry something and let's go 🍓

✨ NAME ✨

hgrc — configuration files for Mercurial. That's it, that's the name. Short, sweet, main character energy.

🌸 DESCRIPTION 🌸

The Mercurial system uses a set of configuration files to control aspects of its behavior. Like, a set. Plural. There's a whole little ecosystem of them and they all have opinions. 💖

🔧 TROUBLESHOOTING 🔧

If you're having problems with your configuration, hg config --source can help you understand what is introducing a setting into your environment. No cap, this is the one that tells you who is responsible for that setting you definitely did not write yourself.

See hg help config.syntax and hg help config.files for information about how and where to override things.

🧚 STRUCTURE 🧚

The configuration files use a simple ini-file format. A configuration file consists of sections, led by a [section] header and followed by name = value entries:

[ui]
username = Firstname Lastname <firstname.lastname@example.net>
verbose = True

The above entries will be referred to as ui.username and ui.verbose, respectively. See hg help config.syntax. So basically <section>.<name> is the whole vibe. 🫶

📁 FILES 📁

Mercurial reads configuration data from several files, if they exist. These files do not exist by default and you will have to create the appropriate configuration files yourself. Like, Mercurial is not gonna make them for you, bestie, that's a you task. 😭

Local configuration is put into the per-repository <repo>/.hg/hgrc file.

Global configuration like the username setting is typically put into:

%USERPROFILE%\mercurial.ini (on Windows)
$HOME/.hgrc (on Unix, Plan9)

The names of these files depend on the system on which Mercurial is installed. *.rc files from a single directory are read in alphabetical order, later ones overriding earlier ones. Where multiple paths are given below, settings from earlier paths override later ones. (Yes, earlier beats later. The way that works is genuinely so specific and I respect it.)

🌈 On Unix, the following files are consulted:

<repo>/.hg/hgrc-not-shared (per-repository)
<repo>/.hg/hgrc (per-repository)
$HOME/.hgrc (per-user)
${XDG_CONFIG_HOME:-$HOME/.config}/hg/hgrc (per-user)
<install-root>/etc/mercurial/hgrc (per-installation)
<install-root>/etc/mercurial/hgrc.d/*.rc (per-installation)
/etc/mercurial/hgrc (per-system)
/etc/mercurial/hgrc.d/*.rc (per-system)
<internal>/*.rc (defaults)

🪟 On Windows, the following files are consulted:

<repo>/.hg/hgrc-not-shared (per-repository)
<repo>/.hg/hgrc (per-repository)
%USERPROFILE%\.hgrc (per-user)
%USERPROFILE%\Mercurial.ini (per-user)
%HOME%\.hgrc (per-user)
%HOME%\Mercurial.ini (per-user)
HKEY_LOCAL_MACHINE\SOFTWARE\Mercurial (per-system)
<install-dir>\hgrc.d\*.rc (per-installation)
<install-dir>\Mercurial.ini (per-installation)
%PROGRAMDATA%\Mercurial\hgrc (per-system)
%PROGRAMDATA%\Mercurial\Mercurial.ini (per-system)
%PROGRAMDATA%\Mercurial\hgrc.d\*.rc (per-system)
<internal>/*.rc (defaults)

Note — The registry key HKEY_LOCAL_MACHINE\SOFTWARE\Wow6432Node\Mercurial is used when running 32-bit Python on 64-bit Windows. Yep, Wow6432Node. That is its actual real name and I will not be making fun of it (out loud).

🦋 On Plan9, the following files are consulted:

<repo>/.hg/hgrc-not-shared (per-repository)
<repo>/.hg/hgrc (per-repository)
$home/lib/hgrc (per-user)
<install-root>/lib/mercurial/hgrc (per-installation)
<install-root>/lib/mercurial/hgrc.d/*.rc (per-installation)
/lib/mercurial/hgrc (per-system)
/lib/mercurial/hgrc.d/*.rc (per-system)
<internal>/*.rc (defaults)

Per-repository configuration options only apply in a particular repository. This file is not version-controlled, and will not get transferred during a clone operation. Options in this file override options in all other configuration files. So it's your private little space, nobody's gonna see it when they clone you. 💅

On Plan 9 and Unix, most of this file will be ignored if it doesn't belong to a trusted user or to a trusted group. See hg help config.trusted for more details. Trust issues but make it security.

Per-user configuration file(s) are for the user running Mercurial. Options in these files apply to all Mercurial commands executed by this user in any directory. Options in these files override per-system and per-installation options.

Per-installation configuration files are searched for in the directory where Mercurial is installed. <install-root> is the parent directory of the hg executable (or symlink) being run.

For example, if installed in /shared/tools/bin/hg, Mercurial will look in /shared/tools/etc/mercurial/hgrc. Options in these files apply to all Mercurial commands executed by any user in any directory.

Per-installation configuration files are for the system on which Mercurial is running. Options in these files apply to all Mercurial commands executed by any user in any directory. Registry keys contain PATH-like strings, every part of which must reference a Mercurial.ini file or be a directory where *.rc files will be read. Mercurial checks each of these locations in the specified order until one or more configuration files are detected.

Per-system configuration files are for the system on which Mercurial is running. Options in these files apply to all Mercurial commands executed by any user in any directory. Options in these files override per-installation options.

Mercurial comes with some default configuration. The default configuration files are installed with Mercurial and will be overwritten on upgrades. Default configuration files should never be edited by users or administrators but can be overridden in other configuration files.

Not you editing the default config files. Put the pen down. 🙈

So far the directory only contains merge tool configuration but packagers can also put other default configuration there.

On versions 5.7 and later, if share-safe functionality is enabled, shares will read config file of share source too. <share-source/.hg/hgrc> is read before reading <repo/.hg/hgrc>.

For configs which should not be shared, <repo/.hg/hgrc-not-shared> should be used. That's literally the whole point of that file, it's in the name, it's giving transparency. ✨

🎀 SYNTAX 🎀

A configuration file consists of sections, led by a [section] header and followed by name = value entries (sometimes called configuration keys):

[spam]
eggs=ham
green=
   eggs

Each line contains one entry. If the lines that follow are indented, they are treated as continuations of that entry. Leading whitespace is removed from values. Empty lines are skipped. Lines beginning with # or ; are ignored and may be used to provide comments.

Configuration keys can be set multiple times, in which case Mercurial will use the value that was configured last. As an example:

[spam]
eggs=large
ham=serrano
eggs=small

This would set the configuration key named eggs to small. Last one wins, periodt. 👑

It is also possible to define a section multiple times. A section can be redefined on the same and/or on different configuration files. For example:

[foo]
eggs=large
ham=serrano
eggs=small

[bar]
eggs=ham
green=
   eggs

[foo]
ham=prosciutto
eggs=medium
bread=toasted

This would set the eggs, ham, and bread configuration keys of the foo section to medium, prosciutto, and toasted, respectively. As you can see there only thing that matters is the last value that was set for each of the configuration keys. (Yes, the original says "there only thing", and honestly? We're keeping it exactly as written, character for character. 💀)

If a configuration key is set multiple times in different configuration files the final value will depend on the order in which the different configuration files are read, with settings from earlier paths overriding later ones as described on the Files section above.

A line of the form %include file will include file into the current configuration file. The inclusion is recursive, which means that included files can include other files. Filenames are relative to the configuration file in which the %include directive is found. Environment variables and ~user constructs are expanded in file. This lets you do something like:

%include ~/.hgrc.d/$HOST.rc

to include a different configuration file on each computer you use. Per-computer configs, we love a personalized touch. 🌈

A line with %unset name will remove name from the current section, if it has been set previously.

The values are either free-form text strings, lists of text strings, or Boolean values. Boolean values can be set to true using any of "1", "yes", "true", or "on" and to false using "0", "no", "false", or "off" (all case insensitive).

List values are separated by whitespace or comma, except when values are placed in double quotation marks:

allow_read = "John Doe, PhD", brian, betty

Quotation marks can be escaped by prefixing them with a backslash. Only quotation marks at the beginning of a word is counted as a quotation (e.g., foo"bar baz is the list of foo"bar and baz).

📚 SECTIONS 📚

This section describes the different sections that may appear in a Mercurial configuration file, the purpose of each section, its possible keys, and their possible values.

🦋 alias

Defines command aliases. You get to make up your own commands, it's giving DIY era.

Aliases allow you to define your own commands in terms of other commands (or aliases), optionally including arguments. Positional arguments in the form of $1, $2, etc. in the alias definition are expanded by Mercurial before execution. Positional arguments not already used by $N in the definition are put at the end of the command to be executed.

Alias definitions consist of lines of the form:

<alias> = <command> [<argument>]...

For example, this definition:

latest = log --limit 5

creates a new command latest that shows only the five most recent changesets. You can define subsequent aliases using earlier ones:

stable5 = latest -b stable

Note — It is possible to create aliases with the same names as existing commands, which will then override the original definitions. This is almost always a bad idea! Like, do not do this. I'm serious. 😭

An alias can start with an exclamation point (!) to make it a shell alias. A shell alias is executed with the shell and will let you run arbitrary commands. As an example,

echo = !echo $@

will let you do hg echo foo to have foo printed in your terminal. A better example might be:

purge = !$HG status --no-status --unknown -0 re: | xargs -0 rm -f

which will make hg purge delete all unknown files in the repository in the same manner as the purge extension. (Yes, that one deletes files. It's a shell alias, it's powerful, be normal about it. 🔥)

Positional arguments like $1, $2, etc. in the alias definition expand to the command arguments. Unmatched arguments are removed. $0 expands to the alias name and $@ expands to all arguments separated by a space. "$@" (with quotes) expands to all arguments quoted individually and separated by a space. These expansions happen before the command is passed to the shell.

Shell aliases are executed in an environment where $HG expands to the path of the Mercurial that was used to execute the alias. This is useful when you want to call further Mercurial commands in a shell alias, as was done above for the purge alias. In addition, $HG_ARGS expands to the arguments given to Mercurial. In the hg echo foo call above, $HG_ARGS would expand to echo foo.

Note — Some global configuration options such as -R are processed before shell aliases and will thus not be passed to aliases. So don't come crying to me when -R doesn't show up in there. 💅

annotate 💖

Okay bestie, these are the settings used when displaying file annotations. All values are Booleans and default to False. See hg help config.diff for related options for the diff command. No cap. 🫶

ignorews — Ignore white space when comparing lines. Literally just skips the spaces, periodt.
ignorewseol — Ignore white space at the end of a line when comparing lines. Trailing spaces? Not today, bestie.
ignorewsamount — Ignore changes in the amount of white space. So if you added three spaces instead of one, it's giving unbothered.
ignoreblanklines — Ignore changes whose lines are all blank. Empty lines? We don't know her. 💅

auth 🔐

Authentication credentials and other authentication-like configuration for HTTP connections. This section allows you to store usernames and passwords for use when logging into HTTP servers. See hg help config.web if you want to configure who can login to your HTTP server. Main character energy for your remote access, fr fr.

The following options apply to all hosts.

cookiefile — Path to a file containing HTTP cookie lines. Cookies matching a host will be sent automatically. Lowkey iconic.

The file format uses the Mozilla cookies.txt format, which defines cookies on their own lines. Each line contains 7 fields delimited by the tab character (domain, is_domain_cookie, path, is_secure, expires, name, value). For more info, do an Internet search for "Netscape cookies.txt format." Iykyk.

Note: the cookies parser does not handle port numbers on domains. You will need to remove ports from the domain for the cookie to be recognized. This could result in a cookie being disclosed to an unwanted server. Not me being dramatic, but that's a whole security vibe check. 😭

The cookies file is read-only. So don't try to edit it, bestie.

Other options in this section are grouped by name and have the following format:

<name>.<argument> = <value>

where <name> is used to group arguments into authentication entries. Example:

foo.prefix = hg.intevation.de/mercurial
foo.username = foo
foo.password = bar
foo.schemes = http https

bar.prefix = secure.example.org
bar.key = path/to/file.key
bar.cert = path/to/file.cert
bar.schemes = https

Supported arguments:

prefix — Either * or a URI prefix with or without the scheme part. The authentication entry with the longest matching prefix is used (where * matches everything and counts as a match of length 1). If the prefix doesn't include a scheme, the match is performed against the URI with its scheme stripped as well, and the schemes argument, q.v., is then subsequently consulted. Slay.
username — Optional. Username to authenticate with. If not given, and the remote site requires basic or digest authentication, the user will be prompted for it. Environment variables are expanded in the username letting you do foo.username = $USER. If the URI includes a username, only [auth] entries with a matching username or without a username will be considered. Obsessed with this flexibility.
password — Optional. Password to authenticate with. If not given, and the remote site requires basic or digest authentication, the user will be prompted for it. Keep it secret, keep it safe. 🎀
key — Optional. PEM encoded client certificate key file. Environment variables are expanded in the filename. Fancy.
cert — Optional. PEM encoded client certificate chain file. Environment variables are expanded in the filename. Also fancy.
schemes — Optional. Space separated list of URI schemes to use this authentication entry with. Only used if the prefix doesn't include a scheme. Supported schemes are http and https. They will match static-http and static-https respectively, as well. (default: https)

If no suitable authentication entry is found, the user is prompted for credentials as usual if required by the remote. The server said "who dis?" and Mercurial will ask you. 🙈

censor 🚫

policy — Control how to react when accessing censored content. Accepted value: "abort", "ignore". Defaults to abort. So by default it's giving "absolutely not."

A few informative commands such as hg grep will unconditionally ignore censored data and merely report that it was encountered. They're not nosy, they just noticed. 💀

cmdserver 🖥️

Controls command server settings. (ADVANCED) Okay advanced bestie, we see you.

message-encodings — List of encodings for the m (message) channel. The first encoding supported by the server will be selected and advertised in the hello message. This is useful only when ui.message-output is set to channel. Supported encodings are cbor. That's it. That's the list.
shutdown-on-interrupt — If set to false, the server's main loop will continue running after SIGINT received. runcommand requests can still be interrupted by SIGINT. Close the write end of the pipe to shut down the server process gracefully. (default: True)

color 🌈

Configure the Mercurial color mode. For details about how to define your custom effect and style see hg help color. The way that Mercurial can be cute is iconic.

mode — String: control the method used to output color. One of auto, ansi, win32, terminfo or debug. In auto mode, Mercurial will use ANSI mode by default (or win32 mode prior to Windows 10) if it detects a terminal. Any invalid value will disable color. So don't be messy with the value, bestie.
pagermode — String: optional override of color.mode used with pager. Highkey useful.

On some systems, terminfo mode may cause problems when using color with less -R as a pager program. less with the -R option will only display ECMA-48 color codes, and terminfo mode may sometimes emit codes that less doesn't understand. You can work around this by either using ansi mode (or auto mode), or by using less -r (which will pass through all terminal control codes, not just color control codes). Not me having flashbacks to broken color codes. 😭

On some systems (such as MSYS in Windows), the terminal may support a different color mode than the pager program. Vibe mismatch, honestly.

commands 🛠️

commit.post-status — Show status of files in the working directory after successful commit. (default: False) So you can see what's still uncommitted. Slay.
merge.require-rev — Require that the revision to merge the current commit with be specified on the command line. If this is enabled and a revision is not specified, the command aborts. (default: False) No guessing games.
push.require-revs — Require revisions to push be specified using one or more mechanisms such as specifying them positionally on the command line, using -r, -b, and/or -B on the command line, or using paths.<path>:pushrev in the configuration. If this is enabled and revisions are not specified, the command aborts. (default: False) Be specific, bestie.
resolve.confirm — Confirm before performing action if no filename is passed. (default: False) Are you sure? Are you sure sure?
resolve.explicit-re-merge — Require uses of hg resolve to specify which action it should perform, instead of re-merging files by default. (default: False) No auto-pilot re-merging.
resolve.mark-check — Determines what level of checking hg resolve --mark will perform before marking files as resolved. Valid values are none, warn, and abort. warn will output a warning listing the file(s) that still have conflict markers in them, but will still mark everything resolved. abort will output the same warning but will not mark things as resolved. If --all is passed and this is set to abort, only a warning will be shown (an error will not be raised). (default: none) Conflict markers are not it, fr fr.
status.relative — Make paths in hg status output relative to the current directory. (default: False) So paths are like "right here" instead of a whole essay.
status.terse — Default value for the --terse flag, which condenses status output. (default: empty) Short and sweet, periodt.
update.check — Determines what level of checking hg update will perform before moving to a destination revision. Valid values are abort, none, linear, and noconflict.
- abort always fails if the working directory has uncommitted changes.
- none performs no checking, and may result in a merge with uncommitted changes.
- linear allows any update as long as it follows a straight line in the revision history, and may trigger a merge with uncommitted changes.
- noconflict will allow any update which would not trigger a merge with uncommitted changes, if any are present. (default: linear) Choose your own adventure, but wisely.
update.requiredest — Require that the user pass a destination when running hg update. For example, hg update .:: will be allowed, but a plain hg update will be disallowed. (default: False) No accidental updates, bestie.

committemplate 📝

changeset — String: configuration in this section is used as the template to customize the text shown in the editor when committing. Make it your own, main character.

In addition to pre-defined template keywords, commit log specific one below can be used for customization:

extramsg — String: Extra message (typically 'Leave message empty to abort commit.'). This may be changed by some commands or extensions. Cute.

For example, the template configuration below shows as same text as one shown by default:

[committemplate]
changeset = {desc}\n\n
    HG: Enter commit message.  Lines beginning with 'HG:' are removed.
    HG: {extramsg}
    HG: --
    HG: user: {author}\n{ifeq(p2rev, "-1", "",
   "HG: branch merge\n")
   }HG: branch '{branch}'\n{if(activebookmark,
   "HG: bookmark '{activebookmark}'\n")   }{subrepos %
   "HG: subrepo {subrepo}\n"              }{file_adds %
   "HG: added {file}\n"                   }{file_mods %
   "HG: changed {file}\n"                 }{file_dels %
   "HG: removed {file}\n"                 }{if(files, "",
   "HG: no files changed\n")}

diff() — String: show the diff (see hg help templates for detail)

Sometimes it is helpful to show the diff of the changeset in the editor without having to prefix 'HG: ' to each line so that highlighting works correctly. For this, Mercurial provides a special string which will ignore everything below it:

HG: ------------------------ >8 ------------------------

For example, the template configuration below will show the diff below the extra message:

[committemplate]
changeset = {desc}\n\n
    HG: Enter commit message.  Lines beginning with 'HG:' are removed.
    HG: {extramsg}
    HG: ------------------------ >8 ------------------------
    HG: Do not touch the line above.
    HG: Everything below will be removed.
    {diff()}

Note For some problematic encodings (see hg help win32mbcs for detail), this customization should be configured carefully, to avoid showing broken characters. Not me warning you to be careful with your encoding, bestie. 🫶

For example, if a multibyte character ending with backslash (0x5c) is followed by the ASCII character n in the customized template, that backslash-plus-n sequence gets treated as a line-feed, completely unexpectedly — and the multibyte character gets broken too. 💀 Not the vibe. Anyway.

Customized template is used for the commands below (--edit may be required):

hg backout
hg commit
hg fetch (for merge commit only)
hg graft
hg histedit
hg import
hg qfold, hg qnew and hg qrefresh
hg rebase
hg shelve
hg sign
hg tag
hg transplant

Configuring the items below instead of changeset lets you show a customized message only for specific actions, or show different messages for each action. 🎯

changeset.backout for hg backout
changeset.commit.amend.merge for hg commit --amend on merges
changeset.commit.amend.normal for hg commit --amend on other
changeset.commit.normal.merge for hg commit on merges
changeset.commit.normal.normal for hg commit on other
changeset.fetch for hg fetch (impling merge commit)
changeset.gpg.sign for hg sign
changeset.graft for hg graft
changeset.histedit.edit for edit of hg histedit
changeset.histedit.fold for fold of hg histedit
changeset.histedit.mess for mess of hg histedit
changeset.histedit.pick for pick of hg histedit
changeset.import.bypass for hg import --bypass
changeset.import.normal.merge for hg import on merges
changeset.import.normal.normal for hg import on other
changeset.mq.qnew for hg qnew
changeset.mq.qfold for hg qfold
changeset.mq.qrefresh for hg qrefresh
changeset.rebase.collapse for hg rebase --collapse
changeset.rebase.merge for hg rebase on merges
changeset.rebase.normal for hg rebase on other
changeset.shelve.shelve for hg shelve
changeset.tag.add for hg tag without --remove
changeset.tag.remove for hg tag --remove
changeset.transplant.merge for hg transplant on merges
changeset.transplant.normal for hg transplant on other

These dot-separated lists of names are treated as hierarchical ones, bestie. So like, changeset.tag.remove customizes the commit message only for hg tag --remove, but changeset.tag customizes the commit message for hg tag regardless of the --remove option. It's giving nested vibes. 🌸

When the external editor is invoked for a commit, the corresponding dot-separated list of names without the changeset. prefix (e.g. commit.normal.normal) is in the HGEDITFORM environment variable. 👑

In this section, items other than changeset can be referred from others. For example, the configuration to list committed files up below can be referred as {listupfiles}:

[committemplate]
listupfiles = {file_adds %
   "HG: added {file}\n"     }{file_mods %
   "HG: changed {file}\n"   }{file_dels %
   "HG: removed {file}\n"   }{if(files, "",
   "HG: no files changed\n")}

🦋 decode/encode 🦋

Filters for transforming files on checkout/checkin. This would typically be used for newline processing or other localization/canonicalization of files.

Filters consist of a filter pattern followed by a filter command. Filter patterns are globs by default, rooted at the repository root. For example, to match any file ending in .txt in the root directory only, use the pattern *.txt. To match any file ending in .c anywhere in the repository, use the pattern **.c. For each file, only the first matching filter applies. First come, first served, no cap. 💅

The filter command can start with a specifier, either pipe: or tempfile:. If no specifier is given, pipe: is used by default.

A pipe: command must accept data on stdin and return the transformed data on stdout.

Pipe example:

[encode]
# uncompress gzip files on checkin to improve delta compression
# note: not necessarily a good idea, just an example
*.gz = pipe: gunzip

[decode]
# recompress gzip files when writing them to the working dir (we
# can safely omit "pipe:", because it's the default)
*.gz = gzip

A tempfile: command is a template. The string INFILE is replaced with the name of a temporary file that contains the data to be filtered by the command. The string OUTFILE is replaced with the name of an empty temporary file, where the filtered data must be written by the command.

Note — The tempfile mechanism is recommended for Windows systems, where the standard shell I/O redirection operators often have strange effects and may corrupt the contents of your files. 🫠 Protect your files, queen.

This filter mechanism is used internally by the eol extension to translate line ending characters between Windows (CRLF) and Unix (LF) format. We suggest you use the eol extension for convenience. ✨

💖 defaults 💖

(defaults are deprecated. Don't use them. Use aliases instead.) 🚫

Use the [defaults] section to define command defaults, i.e. the default options/arguments to pass to the specified commands.

The following example makes hg log run in verbose mode, and hg status show only the modified files, by default:

[defaults]
log = -v
status = -m

The actual commands, instead of their aliases, must be used when defining command defaults. The command defaults will also be applied to the aliases of the commands defined. iykyk. 🎀

🌈 diff 🌈

Settings used when displaying diffs. Everything except for unified is a Boolean and defaults to False. See hg help config.annotate for related options for the annotate command.

git — Use git extended diff format.
merge — Show a "merge diff" instead of defaulting to a diff against the working directory's first parent. A "merge diff" will diff against the conflict regions in the merge, which is very useful to make sense of what the merge commit itself has done.
nobinary — Omit git binary patches.
nodates — Don't include dates in diff headers.
noprefix — Omit a/ and b/ prefixes from filenames. Ignored in plain mode.
showfunc — Show which function each change is in.
ignorews — Ignore white space when comparing lines.
ignorewsamount — Ignore changes in the amount of white space.
ignoreblanklines — Ignore changes whose lines are all blank.
unified — Number of lines of context to show.
word-diff — Highlight changed words.

💌 email 💌

Settings for extensions that send email messages.

from — Optional. Email address to use in "From" header and SMTP envelope of outgoing messages.
to — Optional. Comma-separated list of recipients' email addresses.
cc — Optional. Comma-separated list of carbon copy recipients' email addresses.
bcc — Optional. Comma-separated list of blind carbon copy recipients' email addresses.
method — Optional. Method to use to send email messages. If value is smtp (default), use SMTP (see the [smtp] section for configuration). Otherwise, use as name of program to run that acts like sendmail (takes -f option for sender, list of recipients on command line, message on stdin). Normally, setting this to sendmail or /usr/sbin/sendmail is enough to use sendmail to send messages.
charsets — Optional. Comma-separated list of character sets considered convenient for recipients. Addresses, headers, and parts not containing patches of outgoing messages will be encoded in the first character set to which conversion from local encoding ($HGENCODING, ui.fallbackencoding) succeeds. If correct conversion fails, the text in question is sent as is. (default: '')

Order of outgoing email character sets:

us-ascii: always first, regardless of settings
email.charsets: in order given by user
ui.fallbackencoding: if not in email.charsets
$HGENCODING: if not in email.charsets
utf-8: always last, regardless of settings

Email example:

[email]
from = Joseph User <joe.user@example.com>
method = /usr/sbin/sendmail
# charsets for western Europeans
# us-ascii, utf-8 omitted, as they are tried first and last
charsets = iso-8859-1, iso-8859-15, windows-1252

🧚 extensions 🧚

Mercurial has an extension mechanism for adding new features. To enable an extension, create an entry for it in this section.

If you know that the extension is already in Python's search path, you can give the name of the module, followed by =, with nothing after the =.

Otherwise, give a name that you choose, followed by =, followed by the path to the .py file (including the file name extension) that defines the extension.

To explicitly disable an extension that is enabled in an hgrc of broader scope, prepend its path with !, as in foo = !/ext/path or foo = ! when path is not supplied. 💅

Example for ~/.hgrc:

[extensions]
# (the churn extension will get loaded from Mercurial's path)
churn =
# (this extension will get loaded from the file specified)
myfeature = ~/.hgext/myfeature.py

If an extension fails to load, a warning will be issued, and Mercurial will proceed. To enforce that an extension must be loaded, one can set the required suboption in the config:

[extensions]
myfeature = ~/.hgext/myfeature.py
myfeature:required = yes

To debug extension loading issue, one can add --traceback to their mercurial invocation.

A default setting can we set using the special * extension key:

[extensions]
*:required = yes
myfeature = ~/.hgext/myfeature.py
rebase=

⭐ format ⭐

Configuration that controls the repository format. Newer format options are more powerful, but incompatible with some older versions of Mercurial.

Format options are considered at repository initialization only. You need to make a new clone for config changes to be taken into account. No take-backsies. 😭

For more details about repository format and version compatibility, see https://www.mercurial-scm.org/wiki/MissingRequirement

`usegeneraldelta`

Enable or disable the "generaldelta" repository format which improves repository compression by allowing "revlog" to store deltas against arbitrary revisions instead of the previously stored one. This provides significant improvement for repositories with branches.

Repositories with this on-disk format require Mercurial version 1.9.

Enabled by default. Implied by sparse-revlog

`dotencode`

...it's giving "level up your fncache repository format" 💅 (and yes bestie, fncache has to be enabled for dotencode to work at all, that's the whole deal). What you get out of it: you stop getting absolutely wrecked by filenames that start with ._ on Mac OS X, and by filenames with spaces on Windows. 🌈

Repos with this on-disk format need Mercurial version 1.7.

Enabled by default. ✨

usefncache — turns the fncache repository format on or off. It enhances the store repository format (which, yeah, has to be enabled for fncache to be a thing) so you can have longer filenames, and so you dodge Windows reserved names like nul. 🙈 Repos with this on-disk format need Mercurial version 1.1. Enabled by default.
use-delta-info-flags — stores more info via flags in the revlog's index. Those flags mean more efficient data access, data exchange and data storage in general. 🎀 Specifically, repos using this format can expect better performance than ones using older formats for these categories of commands:
- hg status --copies --rev X
- hg diff
- hg merge
- hg clone
- hg pull
- hg push
- hg unbundle
use-dirstate-v2 — enable or disable the experimental dirstate-v2 feature. The dirstate functionality is shared by literally every command that touches the working copy. The new version is more robust, faster, and stores more information. 👑

Here's the catch, and it's a real one: the performance-improving version of this feature is currently only implemented in Rust (see hg help rust), so if you're not using a Mercurial compiled with the Rust parts, you might actually get some slowdown. For this reason, such versions will by default refuse to access repositories with dirstate-v2 enabled.

You can adjust that behavior via configuration — check hg help config.storage.dirstate-v2.slow-path for the details.

Repos with this on-disk format require Mercurial 6.0 or above.

By default this format variant is disabled if the fast implementation is not available, and enabled by default if the fast implementation is available.

To accommodate Mercurial installations without the fast implementation, you can downgrade your repository. Run this:

$ hg debugupgraderepo \
      --run \
      --config format.use-dirstate-v2=False \
      --config storage.dirstate-v2.slow-path=allow

For a more comprehensive guide, see hg help internals.dirstate-v2.

use-dirstate-v2.automatic-upgrade-of-mismatching-repositories — when enabled, an automatic upgrade gets triggered whenever a repository format doesn't match its use-dirstate-v2 config. 🔥

This is an advanced behavior that most users will not need. We recommend you don't use this unless you are a seasoned administrator of a Mercurial install base.

Automatic upgrade means any process accessing the repository will upgrade the repository format to use dirstate-v2. It only triggers if a change is actually needed. And heads up — this also applies to operations that would have been read-only, like hg status. 😭

If the repository can't be locked, the automatic-upgrade operation will be skipped, and the next operation will attempt it again.

This configuration applies for moves in any direction: either adding the dirstate-v2 format if format.use-dirstate-v2=yes, or removing the dirstate-v2 requirement if format.use-dirstate-v2=no. So we recommend setting both this value and format.use-dirstate-v2 at the same time.

use-dirstate-v2.automatic-upgrade-of-mismatching-repositories:quiet — hides the message when performing such an automatic upgrade. 🤫
use-dirstate-tracked-hint — enable or disable the writing of a "tracked key" file alongside the dirstate. Default is disabled.

That "tracked-hint" can help external automations detect changes to the set of tracked files (i.e. the result of hg files or hg status -macd). 🦋

The tracked-hint is written in a new .hg/dirstate-tracked-hint. That file contains two lines:

the first line is the file version (currently: 1),
the second line contains the "tracked-hint".

That file is written right after the dirstate is written.

The tracked-hint changes whenever the set of files tracked in the dirstate changes. The general idea is:

if the hint is identical, the set of tracked files SHOULD be identical,
if the hint is different, the set of tracked files MIGHT be different.

The "hint is identical" case uses 'SHOULD' because the dirstate and the hint file are two distinct files, so they can't be read or written to in an atomic way. If the key is identical, nothing guarantees that the dirstate isn't updated right after the hint file. This is considered a negligible limitation for the intended use case. It's actually possible to prevent this race by taking the repository lock during read operations. 🔒

There are two "ways" to use this feature:

monitoring changes to the .hg/dirstate-tracked-hint — if the file changes, the tracked set might have changed.
storing the value and comparing it to a later value.

use-dirstate-tracked-hint.automatic-upgrade-of-mismatching-repositories — when enabled, an automatic upgrade gets triggered whenever a repository format doesn't match its use-dirstate-tracked-hint config. 🌸

This is an advanced behavior that most users will not need. We recommend you don't use this unless you are a seasoned administrator of a Mercurial install base.

Automatic upgrade means any process accessing the repository will upgrade the repository format to use dirstate-tracked-hint. It only triggers if a change is needed. This also applies to operations that would have been read-only, like hg status.

If the repository can't be locked, the automatic-upgrade operation will be skipped, and the next operation will attempt it again.

This configuration applies for moves in any direction: either adding the dirstate-tracked-hint format if format.use-dirstate-tracked-hint=yes, or removing the dirstate-tracked-hint requirement if format.use-dirstate-tracked-hint=no. So we recommend setting both this value and format.use-dirstate-tracked-hint at the same time.

use-dirstate-tracked-hint.automatic-upgrade-of-mismatching-repositories:quiet — hides the message when performing such an automatic upgrade. 🤐
use-persistent-nodemap — enable or disable the persistent-nodemap feature, which improves performance if the Rust extensions are available. ⚡

persistent-nodemap persists the "node -> rev" mapping on disk, removing the need to dynamically build that mapping for every single Mercurial invocation. That significantly reduces the startup cost of various local and server-side operations for larger repositories. 📈

The performance-improving version of this feature is currently only implemented in Rust (see hg help rust), so people not using a version of Mercurial compiled with the Rust parts might actually suffer some slowdown. For this reason, such versions will by default refuse to access repositories with persistent-nodemap.

This behavior can be adjusted via configuration — check hg help config.storage.revlog.persistent-nodemap.slow-path for details.

Repos with this on-disk format require Mercurial 5.4 or above.

By default this format variant is disabled if the fast implementation is not available, and enabled by default if the fast implementation is available.

To accommodate Mercurial installations without the fast implementation, you can downgrade your repository. Run this:

$ hg debugupgraderepo \
      --run \
      --config format.use-persistent-nodemap=False \
      --config storage.revlog.persistent-nodemap.slow-path=allow

use-share-safe — enforces "safe" behaviors for all "shares" that access this repository. 🫶

With this feature, "shares" using this repository as a source will:

read the source repository's configuration (<source>/.hg/hgrc).
read and use the source repository's "requirements" (except the working copy specific one).

Without this feature, "shares" using this repository as a source will:

keep tracking the repository "requirements" in the share only, ignoring the source "requirements", possibly diverging from them.
ignore source repository config. This can create problems, like silently ignoring important hooks.

Beware that existing shares will not be upgraded/downgraded, and by default Mercurial will refuse to interact with them until the mismatch is resolved. See hg help config.share.safe-mismatch.source-safe and hg help config.share.safe-mismatch.source-not-safe for details.

Introduced in Mercurial 5.7.

Enabled by default in Mercurial 6.1.

use-share-safe.automatic-upgrade-of-mismatching-repositories — when enabled, an automatic upgrade gets triggered whenever a repository format doesn't match its use-share-safe config. 💫

This is an advanced behavior that most users will not need. We recommend you don't use this unless you are a seasoned administrator of a Mercurial install base.

Automatic upgrade means any process accessing the repository will upgrade the repository format to use share-safe. This only triggers if a change is needed. This also applies to operations that would have been read-only, like hg status.

If the repository can't be locked, the automatic-upgrade operation will be skipped, and the next operation will attempt it again.

okay so this config applies to moves in any direction, bestie — either adding the share-safe format when format.use-share-safe=yes, or removing the share-safe requirement when format.use-share-safe=no. So we highkey recommend you set both this value and format.use-share-safe at the same time. ✨

use-share-safe.automatic-upgrade-of-mismatching-repositories:quiet — Hide the message when one of those automatic upgrades is happening. 🙈
usestore — Turns the store repository format on or off. What does it even do? It improves compatibility with systems that fold case or otherwise mangle filenames, that's what. 🫶 Turning it off lets you store longer filenames in some situations, but at the expense of compatibility, so it's giving tradeoff energy fr.

Repos with this on-disk format need Mercurial version 0.9.4.

Enabled by default. 👑

sparse-revlog — Turns the sparse-revlog delta strategy on or off. This format improves delta re-use inside revlog. For very branchy repositories it results in a smaller store, and for repositories with many revisions it also helps performance (by using shortened delta chains). Basically it eats. 💅

Repositories with this on-disk format require Mercurial version 4.7.

Implies usegeneraldelta.

Enabled by default. ✨

revlog-compression — The compression algorithm revlog uses. Supported values are zlib and zstd. The zlib engine is the historical default of Mercurial. zstd is a newer format that is usually a net win over zlib, operating faster at better compression rates — use zstd to reduce CPU usage. You can specify multiple values, and the first available one gets used. 🌈

Heads up: on some systems, the Mercurial installation may lack zstd support. 😭

Default is zstd if available, zlib otherwise.

bookmarks-in-store — Store bookmarks in .hg/store/. This means bookmarks are shared when using hg share regardless of the -B option. Bestie that's the whole vibe. 🎀

Repositories with this on-disk format require Mercurial version 5.1.

Disabled by default.

🦋 GRAPH 🦋

Web graph view configuration. This section lets you change graph elements' display properties by branch — for instance, to make the default branch stand out and be the main character. 👑

Every line has this format:

<branch>.<argument> = <value>

where <branch> is the name of the branch you're customizing. Example:

[graph]
# 2px width
default.width = 2
# red color
default.color = FF0000

Supported arguments:

width — Set branch edges width in pixels. 📏
color — Set branch edges color in hexadecimal RGB notation. 🎨

🫶 HOOKS 🫶

Commands or Python functions that get automatically executed by various actions, like starting or finishing a commit. Multiple hooks can run for the same action — you just append a suffix to the action. Want to override a site-wide hook? Change its value, or set it to an empty string. Hooks can be prioritized by adding a prefix of priority. to the hook name on a new line and setting the priority. The default priority is 0. ✨

Example .hg/hgrc:

[hooks]
# update working directory after adding changesets
changegroup.update = hg update
# do not use the site-wide hook
incoming =
incoming.email = /my/email/hook
incoming.autobuild = /my/build/hook
# force autobuild hook to run before other incoming hooks
priority.incoming.autobuild = 1
###  control HGPLAIN setting when running autobuild hook
# HGPLAIN always set (default from Mercurial 5.7)
incoming.autobuild:run-with-plain = yes
# HGPLAIN never set
incoming.autobuild:run-with-plain = no
# HGPLAIN inherited from environment (default before Mercurial 5.7)
incoming.autobuild:run-with-plain = auto

Most hooks run with environment variables set that give you useful extra info. For each hook below, the environment variables it's passed are listed with names in the form $HG_foo. The $HG_HOOKTYPE and $HG_HOOKNAME variables are set for all hooks — they contain the type of hook that triggered the run, and the full name of the hook in the config, respectively. In the example above, that's $HG_HOOKTYPE=incoming and $HG_HOOKNAME=incoming.email. 🧚

Some basic Unix syntax can be enabled for portability, including $VAR and ${VAR} style variables. A ~ followed by \ or / will be expanded to %USERPROFILE% to simulate a subset of tilde expansion on Unix. To use a literal $ or ~, it must be escaped with a back slash or inside of a strong quote. Strong quotes will be replaced by double quotes after processing. 😌

This feature is enabled by adding a prefix of tonative. to the hook name on a new line, and setting it to True. For example:

[hooks]
incoming.autobuild = /my/build/hook
# enable translation to cmd.exe syntax for autobuild hook
tonative.incoming.autobuild = True

changegroup — Run after a changegroup has been added via push, pull or unbundle. The ID of the first new changeset is in $HG_NODE and last is in $HG_NODE_LAST. The URL from which changes came is in $HG_URL. 🔥
commit — Run after a changeset has been created in the local repository. The ID of the newly created changeset is in $HG_NODE. Parent changeset IDs are in $HG_PARENT1 and $HG_PARENT2. 💖
incoming — Run after a changeset has been pulled, pushed, or unbundled into the local repository. The ID of the newly arrived changeset is in $HG_NODE. The URL that was the source of the changes is in $HG_URL. 📥
outgoing — Run after sending changes from the local repository to another. The ID of the first changeset sent is in $HG_NODE. The source of the operation is in $HG_SOURCE. Also see hg help config.hooks.preoutgoing. 📤
post-<command> — Run after successful invocations of the associated command. The contents of the command line are passed as $HG_ARGS and the result code in $HG_RESULT. Parsed command line arguments are passed as $HG_PATS and $HG_OPTS. These contain string representations of the python data internally passed to <command>. $HG_OPTS is a dictionary of options (with unspecified options set to their defaults). $HG_PATS is a list of arguments. Hook failure is ignored. 🫠
fail-<command> — Run after a failed invocation of an associated command. The contents of the command line are passed as $HG_ARGS. Parsed command line arguments are passed as $HG_PATS and $HG_OPTS. These contain string representations of the python data internally passed to <command>. $HG_OPTS is a dictionary of options (with unspecified options set to their defaults). $HG_PATS is a list of arguments. Hook failure is ignored. 💀
pre-<command> — Run before executing the associated command. The contents of the command line are passed as $HG_ARGS. Parsed command line arguments are passed as $HG_PATS and $HG_OPTS. These contain string representations of the data internally passed to <command>. $HG_OPTS is a dictionary of options (with unspecified options set to their defaults). $HG_PATS is a list of arguments. If the hook returns failure, the command doesn't execute and Mercurial returns the failure code. 🚨
prechangegroup — Run before a changegroup is added via push, pull or unbundle. Exit status 0 allows the changegroup to proceed. A non-zero status will cause the push, pull or unbundle to fail. The URL from which changes will come is in $HG_URL. ✋
precommit — Run before starting a local commit. Exit status 0 allows the commit to proceed. A non-zero status will cause the commit to fail. Parent changeset IDs are in $HG_PARENT1 and $HG_PARENT2. 🛑
prelistkeys — Run before listing pushkeys (like bookmarks) in the repository. A non-zero status will cause failure. The key namespace is in $HG_NAMESPACE. 🔑
preoutgoing — Run before collecting changes to send from the local repository to another. A non-zero status will cause failure. This lets you prevent pull over HTTP or SSH. It can also prevent propagating commits (via local pull, push (outbound) or bundle commands), but not completely — since you can just copy files instead, bestie, no cap. The source of the operation is in $HG_SOURCE. If "serve", the operation is happening on behalf of a remote SSH or HTTP repository. If "push", "pull" or "bundle", the operation is happening on behalf of a repository on the same system. 🙅
prepushkey — Run before a pushkey (like a bookmark) is added to the repository. A non-zero status will cause the key to be rejected. The key namespace is in $HG_NAMESPACE, the key is in $HG_KEY, the old value (if any) is in $HG_OLD, and the new value is in $HG_NEW. 🎯
pretag — Run before creating a tag. Exit status 0 allows the tag to be created. A non-zero status will cause the tag to fail. The ID of the changeset to tag is in $HG_NODE. The name of the tag is in $HG_TAG. The tag is local if $HG_LOCAL=1, or in the repository if $HG_LOCAL=0. 🏷️
pretransmit-inline-clone-bundle — Run before transferring an inline clonebundle to the peer. If the exit status is 0, the inline clonebundle will be allowed to be transferred. A non-zero status will cause the transfer to fail. The path of the inline clonebundle is in $HG_CLONEBUNDLEPATH. 📦
pretxnopen — Run before any new repository transaction is open. The reason for the transaction will be in $HG_TXNNAME, and a unique identifier for the transaction will be in $HG_TXNID. A non-zero status will prevent the transaction from being opened. 🚪
pretxnclose

So bestie, this one runs right before the transaction is actually finalized. Any repository change will be visible to the hook program. This lets you validate the transaction content or change it. Exit status 0 allows the commit to proceed. A non-zero status will cause the transaction to be rolled back. The reason for the transaction opening will be in $HG_TXNNAME, and a unique identifier for the transaction will be in $HG_TXNID. The rest of the available data will vary according the transaction type. Changes unbundled to the repository will add $HG_URL and $HG_SOURCE. New changesets will add $HG_NODE (the ID of the first added changeset), $HG_NODE_LAST (the ID of the last added changeset). Bookmark and phase changes will set $HG_BOOKMARK_MOVED and $HG_PHASES_MOVED to 1 respectively. The number of new obsmarkers, if any, will be in $HG_NEW_OBSMARKERS, etc.

`pretxnclose-bookmark` ✨

Run right before a bookmark change is actually finalized. Any repository change will be visible to the hook program. This lets you validate the transaction content or change it. Exit status 0 allows the commit to proceed. A non-zero status will cause the transaction to be rolled back. The name of the bookmark will be available in $HG_BOOKMARK, the new bookmark location will be available in $HG_NODE while the previous location will be available in $HG_OLDNODE. In case of a bookmark creation $HG_OLDNODE will be empty. In case of deletion $HG_NODE will be empty. In addition, the reason for the transaction opening will be in $HG_TXNNAME, and a unique identifier for the transaction will be in $HG_TXNID.

`pretxnclose-phase` 🌙

Run right before a phase change is actually finalized. Any repository change will be visible to the hook program. This lets you validate the transaction content or change it. Exit status 0 allows the commit to proceed. A non-zero status will cause the transaction to be rolled back. The hook is called multiple times, once for each revision affected by a phase change. The affected node is available in $HG_NODE, the phase in $HG_PHASE while the previous $HG_OLDPHASE. In case of new node, $HG_OLDPHASE will be empty. In addition, the reason for the transaction opening will be in $HG_TXNNAME, and a unique identifier for the transaction will be in $HG_TXNID. The hook is also run for newly added revisions. In this case the $HG_OLDPHASE entry will be empty.

`txnclose` 🎉

Run after any repository transaction has been committed. At this point, the transaction can no longer be rolled back. The hook will run after the lock is released. See hg help config.hooks.pretxnclose for details about available variables.

`txnclose-bookmark` 📚

Run after any bookmark change has been committed. At this point, the transaction can no longer be rolled back. The hook will run after the lock is released. See hg help config.hooks.pretxnclose-bookmark for details about available variables.

`txnclose-phase` 🌈

Run after any phase change has been committed. At this point, the transaction can no longer be rolled back. The hook will run after the lock is released. See hg help config.hooks.pretxnclose-phase for details about available variables.

`txnabort` 💀

Run when a transaction is aborted. See hg help config.hooks.pretxnclose for details about available variables.

`pretxnchangegroup` 🫶

Run after a changegroup has been added via push, pull or unbundle, but before the transaction has been committed. The changegroup is visible to the hook program. This allows validation of incoming changes before accepting them. The ID of the first new changeset is in $HG_NODE and last is in $HG_NODE_LAST. Exit status 0 allows the transaction to commit. A non-zero status will cause the transaction to be rolled back, and the push, pull or unbundle will fail. The URL that was the source of changes is in $HG_URL.

`pretxncommit` 📝

Run after a changeset has been created, but before the transaction is committed. The changeset is visible to the hook program. This allows validation of the commit message and changes. Exit status 0 allows the commit to proceed. A non-zero status will cause the transaction to be rolled back. The ID of the new changeset is in $HG_NODE. The parent changeset IDs are in $HG_PARENT1 and $HG_PARENT2.

`preupdate` 🔄

Run before updating the working directory. Exit status 0 allows the update to proceed. A non-zero status will prevent the update. The changeset ID of first new parent is in $HG_PARENT1. If updating to a merge, the ID of second new parent is in $HG_PARENT2.

`listkeys` 🗝️

Run after listing pushkeys (like bookmarks) in the repository. The key namespace is in $HG_NAMESPACE. $HG_VALUES is a dictionary containing the keys and values.

`pushkey` 🔑

Run after a pushkey (like a bookmark) is added to the repository. The key namespace is in $HG_NAMESPACE, the key is in $HG_KEY, the old value (if any) is in $HG_OLD, and the new value is in $HG_NEW.

`tag` 🏷️

Run after a tag is created. The ID of the tagged changeset is in $HG_NODE. The name of tag is in $HG_TAG. The tag is local if $HG_LOCAL=1, or in the repository if $HG_LOCAL=0.

`update` ⬆️

Run after updating the working directory. The changeset ID of first new parent is in $HG_PARENT1. If updating to a merge, the ID of second new parent is in $HG_PARENT2. If the update succeeded, $HG_ERROR=0. If the update failed (e.g. because conflicts were not resolved), $HG_ERROR=1.

`prelock` 🔒

Runs before the store lock is taken, mostly used for test and debug.

`prewlock` 🔐

Runs before the working copy lock is taken, mostly used for test and debug.

Note — It is generally better to use standard hooks rather than the generic pre- and post- command hooks, as they are guaranteed to be called in the appropriate contexts for influencing transactions. Also, hooks like "commit" will be called in all contexts that generate a commit (e.g. tag) and not just the commit command.

Note — Environment variables with empty values may not be passed to hooks on platforms such as Windows. As an example, $HG_PARENT2 will have an empty value under Unix-like platforms for non-merge changesets, while it will not be available at all under Windows.

The syntax for Python hooks is as follows:

hookname = python:modulename.submodule.callable
hookname = python:/path/to/python/module.py:callable

Python hooks are run within the Mercurial process. Each hook is called with at least three keyword arguments: a ui object (keyword ui), a repository object (keyword repo), and a hooktype keyword that tells what kind of hook is used. Arguments listed as environment variables above are passed as keyword arguments, with no HG_ prefix, and names in lower case.

If a Python hook returns a "true" value or raises an exception, this is treated as a failure.

`hostfingerprints` 💅

(Deprecated. Use [hostsecurity]'s fingerprints options instead.)

Fingerprints of the certificates of known HTTPS servers.

A HTTPS connection to a server with a fingerprint configured here will only succeed if the servers certificate matches the fingerprint. This is very similar to how ssh known hosts works.

The fingerprint is the SHA-1 hash value of the DER encoded certificate. Multiple values can be specified (separated by spaces or commas). This can be used to define both old and new fingerprints while a host transitions to a new certificate.

The CA chain and web.cacerts is not used for servers with a fingerprint.

For example:

[hostfingerprints]
hg.intevation.de = fc:e2:8d:d9:51:cd:cb:c1:4d:18:6b:b7:44:8d:49:72:57:e6:cd:33
hg.intevation.org = fc:e2:8d:d9:51:cd:cb:c1:4d:18:6b:b7:44:8d:49:72:57:e6:cd:33

`hostsecurity` 🔐

Used to specify global and per-host security settings for connecting to other machines.

The following options control default behavior for all hosts.

`ciphers` 🔒

Defines the cryptographic ciphers to use for connections.

Value must be a valid OpenSSL Cipher List Format as documented at https://www.openssl.org/docs/manmaster/apps/ciphers.html#CIPHER-LIST-FORMAT .

This setting is for advanced users only. Setting to incorrect values can significantly lower connection security or decrease performance. You have been warned.

This option requires Python 2.7.

`minimumprotocol` 🛡️

Defines the minimum channel encryption protocol to use in the client.

By default, the highest version of TLS supported by both client and server is used.

Allowed values are: tls1.0, tls1.1, tls1.2, tls1.3.

Depending on the version of Python being used, not all of these values may be available. See hg debuginstall for the values supported by the current installation.

When running a Python that supports modern TLS versions, the default is tls1.2. tls1.0 and tls1.1 can still be used to allow TLS 1.0 or TLS 1.1 respectively, if supported by Python. However, this weakens security and should only be used as a feature of last resort if a server does not support TLS 1.2+.

Options in the [hostsecurity] section can have the form hostname:setting. This allows multiple settings to be defined on a per-host basis.

The following per-host settings can be defined.

`ciphers` 🔒

This behaves like ciphers as described above except it only applies to the host on which it is defined.

`fingerprints` 🫰

A list of hashes of the DER encoded peer/remote certificate. Values have the form algorithm:fingerprint. e.g. sha256:c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2. In addition, colons (:) can appear in the fingerprint part.

The following algorithms/prefixes are supported: sha1, sha256, sha512.

Use of sha256 or sha512 is preferred.

So if you've specified a fingerprint, bestie: the CA chain is not validated for that host, and Mercurial will make the remote certificate match one of the fingerprints you gave it. Which means 😬 if the server ever updates its certificate, Mercurial just aborts until you define a fresh fingerprint. This buys you stronger security than the traditional CA-based validation thing — at the cost of convenience. Trade-offs, we love them.

This option takes precedence over verifycertsfile.

🎀 `minimumprotocol`

This behaves like minimumprotocol as described above except it only applies to the host on which it is defined.

🎀 `verifycertsfile`

Path to a file containing a list of PEM encoded certificates used to verify the server certificate. Environment variables and ~user constructs get expanded in the filename. ✨

The server certificate — or that certificate's certificate authority (CA) — must match a certificate from this file, otherwise certificate verification fails and connections to the server get refused. No vibes, no connection. 🚫

If this is defined, only the certificates from this file are used: web.cacerts and any system/default certificates are not used. Periodt.

This option has no effect if the per-host fingerprints option is set.

The format of the file is literally this:

-----BEGIN CERTIFICATE-----
... (certificate in base64 PEM encoding) ...
-----END CERTIFICATE-----
-----BEGIN CERTIFICATE-----
... (certificate in base64 PEM encoding) ...
-----END CERTIFICATE-----

For example:

[hostsecurity]
hg.example.com:fingerprints = sha256:c3ab8ff13720e8ad9047dd39466b3c8974e592c2fa383d4a3960714caef0c4f2
hg2.example.com:fingerprints = sha1:914f1aff87249c09b6859b88b1906d30756491ca, sha1:fc:e2:8d:d9:51:cd:cb:c1:4d:18:6b:b7:44:8d:49:72:57:e6:cd:33
hg3.example.com:fingerprints = sha256:9a:b0:dc:e2:75:ad:8a:b7:84:58:e5:1f:07:32:f1:87:e6:bd:24:22:af:b7:ce:8e:9c:b4:10:cf:b9:f4:0e:d2
foo.example.com:verifycertsfile = /etc/ssl/trusted-ca-certs.pem

And to change the default minimum protocol version to TLS 1.2, but still allow TLS 1.1 when connecting to hg.example.com:

[hostsecurity]
minimumprotocol = tls1.2
hg.example.com:minimumprotocol = tls1.1

🌈 http_proxy

Used to access web-based Mercurial repositories through a HTTP proxy. 🕵️‍♀️

host — Host name and (optional) port of the proxy server, for example "myproxy:8000".
no — Optional. Comma-separated list of host names that should bypass the proxy.
passwd — Optional. Password to authenticate with at the proxy server.
user — Optional. User name to authenticate with at the proxy server.
always — Optional. Always use the proxy, even for localhost and any entries in http_proxy.no. (default: False)

🌸 http

Used to configure access to Mercurial repositories via HTTP. 🌐

timeout — If set, blocking operations will timeout after that many seconds. (default: None)

💜 merge

This section specifies behavior during merges and updates. 🫶

⭐ `checkignored`

Controls behavior when an ignored file on disk has the same name as a tracked file in the changeset being merged or updated to, and has different contents. Options are abort, warn and ignore. With abort, abort on such files. With warn, warn on such files and back them up as .orig. With ignore, don't print a warning and back them up as .orig. (default: abort)

⭐ `checkunknown`

Controls behavior when an unknown file that isn't ignored has the same name as a tracked file in the changeset being merged or updated to, and has different contents. Similar to merge.checkignored, except for files that are not ignored. (default: abort)

⭐ `on-failure`

When set to continue (the default), the merge process attempts to merge all unresolved files using the merge chosen tool, regardless of whether previous file merge attempts during the process succeeded or not. Setting this to prompt will prompt after any merge failure to continue or halt the merge process. Setting this to halt will automatically halt the merge process on any merge tool failure. The merge process can be restarted by using the resolve command. When a merge is halted, the repository is left in a normal unresolved merge state. (default: continue)

⭐ `strict-capability-check`

Whether capabilities of internal merge tools are checked strictly or not, while examining rules to decide merge tool to be used. (default: False)

🦋 merge-patterns

This section specifies merge tools to associate with particular file patterns. Tools matched here take precedence over the default merge tool. Patterns are globs by default, rooted at the repository root. 🎯

Example:

[merge-patterns]
**.c = kdiff3
**.jpg = myimgmerge

👑 merge-tools

This section configures external merge tools to use for file-level merges. This section has likely been preconfigured at install time. Use hg config merge-tools to check the existing configuration. Also see hg help merge-tools for more details. 💅

Example ~/.hgrc:

[merge-tools]
# Override stock tool location
kdiff3.executable = ~/bin/kdiff3
# Specify command line
kdiff3.args = $base $local $other -o $output
# Give higher priority
kdiff3.priority = 1

# Changing the priority of preconfigured tool
meld.priority = 0

# Disable a preconfigured tool
vimdiff.disabled = yes

# Define new tool
myHtmlTool.args = -m $local $other $base $output
myHtmlTool.regkey = Software\FooSoftware\HtmlMerge
myHtmlTool.priority = 1

Supported arguments:

✨ `priority`

The priority in which to evaluate this tool. (default: 0)

✨ `executable`

Either just the name of the executable or its pathname.

On Windows, the path can use environment variables with ${ProgramFiles} syntax.

(default: the tool name)

✨ `args`

The arguments to pass to the tool executable. You can refer to the files being merged as well as the output file through these variables: $base, $local, $other, $output.

The meaning of $local and $other can vary depending on which action is being performed. During an update or merge, $local represents the original state of the file, while $other represents the commit you are updating to or the commit you are merging with. During a rebase, $local represents the destination of the rebase, and $other represents the commit being rebased.

Some operations define custom labels to assist with identifying the revisions, accessible via $labellocal, $labelother, and $labelbase. If custom labels are not available, these will be local, other, and base, respectively. (default: $local $base $other)

✨ `premerge`

Attempt to run internal non-interactive 3-way merge tool before launching external tool. Options are true, false, keep, keep-merge3, or keep-mergediff (experimental). The keep option will leave markers in the file if the premerge fails. The keep-merge3 will do the same but include information about the base of the merge in the marker (see internal :merge3 in hg help merge-tools). The keep-mergediff option is similar but uses a different marker style (see internal :merge3 in hg help merge-tools). (default: True)

✨ `binary`

This tool can merge binary files. (default: False, unless tool was selected by file pattern match)

✨ `symlink`

This tool can merge symlinks. (default: False)

✨ `check`

A list of merge success-checking options:

changed — Ask whether merge was successful when the merged file shows no changes.
conflicts — Check whether there are conflicts even though the tool reported success.
prompt — Always prompt for merge success, regardless of success reported by tool.

✨ `fixeol`

Attempt to fix up EOL changes caused by the merge tool. (default: False)

✨ `gui`

This tool requires a graphical interface to run. (default: False)

✨ `mergemarkers`

Controls whether the labels passed via $labellocal, $labelother, and $labelbase are detailed (respecting mergemarkertemplate) or basic. If premerge is keep or keep-merge3, the conflict markers generated during premerge will be detailed if either this option or the corresponding option in the [ui] section is detailed. (default: basic)

✨ `mergemarkertemplate`

This setting can be used to override mergemarker from the [command-templates] section on a per-tool basis; this applies to the $label-prefixed variables and to the conflict markers that are generated if premerge is keep or keep-merge3. See the corresponding variable in [ui] for more information.

✨ `regkey`

Windows registry key which describes install location of this tool. Mercurial will search for this key first under HKEY_CURRENT_USER and then under HKEY_LOCAL_MACHINE. (default: None)

✨ `regkeyalt`

An alternate Windows registry key to try if the first key is not found. The alternate key uses the same regname and regappend semantics of the primary key. The most common use for this key is to search for 32bit applications on 64bit operating systems. (default: None)

✨ `regname`

Name of value to read from specified registry key. (default: the unnamed (default) value)

✨ `regappend`

String to append to the value read from the registry, typically the executable name of the tool. (default: None)

Setting used to control when to paginate and with what external tool. See hg help pager for details. 📄

🌟 `pager`

Define the external tool used as pager.

If no pager is set, Mercurial uses the environment variable $PAGER. If neither pager.pager, nor $PAGER is set, a default pager will be used, typically less on Unix and more on Windows. Example:

[pager]
pager = less -FRX

🌟 `ignore`

List of commands to disable the pager for. Example:

[pager]
ignore = version, help, update

🧚 patch

Settings used when applying patches, for instance through the import command or with Mercurial Queues extension. 🩹

eol —

When it's set to 'strict', bestie, the end-of-lines in both the patch content and the patched files are preserved, periodt. When it's lf or crlf, both files' end-of-lines get ignored while patching and the resulting line endings get normalized to either LF (Unix) or CRLF (Windows). When it's auto, the end-of-lines are ignored again while patching, but the line endings in the patched files get normalized to their original setting, on a per-file basis. And if the target file doesn't exist or has no end-of-line at all? Then the patch line endings are preserved. (default: strict)

fuzz

The number of lines of 'fuzz' to allow when applying patches. This is the vibe check on how much context the patcher is allowed to ignore while trying to apply a patch. (default: 2)

✨ paths ✨

Assigns symbolic names and behavior to repositories. It's giving nickname energy 🎀

The options are symbolic names that define the URL or directory that's the location of the repository. Example:

[paths]
my_server = https://example.com/my_repo
local_path = /home/me/repo

These symbolic names can be used right from the command line. Wanna pull from my_server? Just hg pull my_server. Wanna push to local_path? hg push local_path. And you can check hg help urls for the deets about valid URLs. 💅

Options containing colons (:) denote sub-options that can influence behavior for that specific path. Example:

[paths]
my_server = https://example.com/my_path
my_server:pushurl = ssh://example.com/my_path

Paths using the path://otherpath scheme will inherit the sub-options value from the path they point to. So iconic of them.

The following sub-options can be defined:

multi-urls

A boolean option. When enabled, the value of the [paths] entry will be parsed as a list, and the alias will resolve to multiple destinations. If some of the list entries use the path:// syntax, the suboption will be inherited individually.

pushurl

The URL to use for push operations. If it's not defined, the location defined by the path's main entry is used.

pushrev

A revset defining which revisions to push by default.

When hg push is executed without a -r argument, the revset defined by this sub-option is evaluated to determine what to push.

For example, a value of . will push the working directory's revision by default.

Heads up bestie: revsets specifying bookmarks will not result in the bookmark being pushed. 😭

bookmarks.mode

How bookmark will be dealt during the exchange. It supports the following values:

default: the default behavior, local and remote bookmarks are "merged" on push/pull.
mirror: when pulling, replace local bookmarks by remote bookmarks. This is useful to replicate a repository, or as an optimization.
ignore: ignore bookmarks during exchange. (This currently only affect pulling)

pulled-delta-reuse-policy

Control the policy regarding deltas sent by the remote during pulls.

This is an advanced option that non-admin users should not need to understand or set. It can be used to speed up pulls from trusted central servers, or to fix-up deltas from older servers. 🔥

It supports the following values:

default: use the policy defined by storage.revlog.reuse-external-delta-parent,
no-reuse: start a new optimal delta search for each new revision we add to the repository. The deltas from the server will be reused when the base it applies to is tested (this can be frequent if that base is the one and unique parent of that revision). This can significantly slowdown pulls but will result in an optimized storage space if the remote peer is sending poor quality deltas.
try-base: try to reuse the deltas from the remote peer as long as they create a valid delta-chain in the local repository. This speeds up the unbundling process, but can result in sub-optimal storage space if the remote peer is sending poor quality deltas.
forced: the deltas from the peer will be reused in all cases, even if the resulting delta-chain is "invalid". This setting will ensure the bundle is applied at minimal CPU cost, but it can result in longer delta chains being created on the client, making revisions potentially slower to access in the future. If you think you need this option, you should make sure you are also talking to the Mercurial developer community to get confirmation. 👑

See hg help config.storage.revlog.reuse-external-delta-parent for a similar global option. That option defines the behavior of default.

The following special named paths exist:

default

The URL or directory to use when no source or remote is specified.

hg clone will automatically define this path to the location the repository was cloned from.

default-push

(deprecated) The URL or directory for the default hg push location. default:pushurl should be used instead.

Not me using a deprecated option 🙈 use default:pushurl instead, bestie.

✨ phases ✨

Specifies default handling of phases. See hg help phases for more info about working with phases. 🌙

publish

Controls draft phase behavior when working as a server. When true, pushed changesets are set to public in both client and server, and pulled or cloned changesets are set to public in the client. (default: True)

new-commit

Phase of newly-created commits. (default: draft)

checksubrepos

Check the phase of the current revision of each subrepository. Allowed values are "ignore", "follow" and "abort". For settings other than "ignore", the phase of the current revision of each subrepository is checked before committing the parent repository. If any of those phases is greater than the phase of the parent repository (e.g. if a subrepo is in a "secret" phase while the parent repo is in "draft" phase), the commit is either aborted (if checksubrepos is set to "abort") or the higher phase is used for the parent repository commit (if set to "follow"). (default: follow)

✨ profiling ✨

Specifies profiling type, format, and file output. Two profilers are supported: an instrumenting profiler (named ls), and a sampling profiler (named stat). 🔍

In this section description, 'profiling data' stands for the raw data collected during profiling, while 'profiling report' stands for a statistical text report generated from the profiling data.

enabled

Enable the profiler. (default: false)

This is equivalent to passing --profile on the command line.

type

The type of profiler to use. (default: stat)

ls

Use Python's built-in instrumenting profiler. This profiler works on all platforms, but each line number it reports is the first line of a function. This restriction makes it difficult to identify the expensive parts of a non-trivial function. 😭

stat

Use a statistical profiler, statprof. This profiler is most useful for profiling commands that run for longer than about 0.1 seconds.

py-spy

use the py-spy profiler. A external py-spy executable must be available. (Make sure to check profiling.output config to write the result.)

format

Profiling format. Specific to the ls instrumenting profiler. (default: text)

text

Generate a profiling report. When saving to a file, it should be noted that only the report is saved, and the profiling data is not kept.

kcachegrind

Format profiling data for kcachegrind use: when saving to a file, the generated file can directly be loaded into kcachegrind.

statformat

Profiling format for the stat profiler. (default: hotpath)

hotpath

Show a tree-based display containing the hot path of execution (where most time was spent). 🔥

bymethod

Show a table of methods ordered by how frequently they are active.

byline

Show a table of lines in files ordered by how frequently they are active.

json

Render profiling data as JSON.

freq

Sampling frequency. Specific to the stat sampling profiler. (default: 1000)

output

File path where profiling data or report should be saved. If the file exists, it is replaced. (default: None, data is printed on stderr)

output-dir

Directory in which profiling data or report should be saved. The data will be written to a file with the naming scheme "hg-profile-{TIMESTAMP}-{PID}.prof". If both output and output-dir are specified, output will take precedence.

output-dir:create

Create output-dir if it doesn't already exist.

sort

Sort field. Specific to the ls instrumenting profiler. One of callcount, reccallcount, totaltime and inlinetime. (default: inlinetime)

time-track

Control if the stat profiler track cpu or real time. (default: cpu on Windows, otherwise real)

limit

Number of lines to show. Specific to the ls instrumenting profiler. (default: 30)

nested

Show at most this number of lines of drill-down info after each main entry. This can help explain the difference between Total and Inline. Specific to the ls instrumenting profiler. (default: 0)

showmin

Minimum fraction of samples an entry must have for it to be displayed. Can be specified as a float between 0.0 and 1.0 or can have a % afterwards to allow values up to 100. e.g. 5%.

Only used by the stat profiler.

For the hotpath format, default is 0.05. For the chrome format, default is 0.005.

The option is unused on other formats.

showmax

Maximum fraction of samples an entry can have before it is ignored in display. Values format is the same as showmin.

Only used by the stat profiler.

For the chrome format, default is 0.999.

The option is unused on other formats.

showtime

Show time taken as absolute durations, in addition to percentages. Only used by the hotpath format. (default: true)

✨ progress ✨

Mercurial commands can draw progress bars that are as informative as possible. Some progress bars only offer indeterminate information, while others have a definite end point. 📊✨

debug — do we print debug info while updating the progress bar? (default: False)
delay — how many seconds (float, bestie, it can be a decimal) before the progress bar even shows up. (default: 3)
changedelay — minimum delay before showing a new topic. If you set it to anything less than 3 * refresh, then that value gets used instead. (default: 1)
estimateinterval — the max sampling interval in seconds for the speed and estimated-time math. (default: 60)
refresh — time in seconds between refreshes of the progress bar. (default: 0.1)
format — the format of the progress bar, aka its whole lewk ✨

Valid entries for the format field are topic, bar, number, unit, estimate, speed, and item. item defaults to the last 20 characters of the item, but you can change that by adding either -<num>, which takes the last num characters, or +<num>, which takes the first num characters.

(default: topic bar number estimate)

width — if set, this is the maximum width of the progress information (so like, min(width, term width) gets used).
clear-complete — clear the progress bar once it's done. (default: True)
disable — if true, no progress bar for you, sorry. 🙈
assume-tty — if true, ALWAYS show a progress bar, unless disable is given.

🌀 rebase 🌀

evolution.allowdivergence — defaults to False. When it's True, you're allowed to create divergence while performing a rebase of obsolete changesets. (Chaos, but make it consensual.)

🪄 revsetalias 🪄

Alias definitions for revsets. See hg help revsets for the details, bestie.

♻️ rewrite ♻️

backup-bundle — whether to save stripped changesets to a bundle file. (default: True)
update-timestamp — if true, updates the date and time of the changeset to current. In the current version it's only applicable for hg amend, hg commit --amend and hg uncommit.
empty-successor — controls what happens with empty successors that are the result of rewrite operations. If set to skip, the successor is not created. If set to keep, the empty successor is created and kept.

Currently, only the rebase and absorb commands consider this configuration. (EXPERIMENTAL)

🦀 rhg 🦀

The pure Rust fast-path for Mercurial. See rust/README.md in the Mercurial repository.

fallback-executable — path to the executable to run in a sub-process when falling back to another implementation of Mercurial.
fallback-immediately — fall back to fallback-executable as soon as possible, regardless of the rhg.on-unsupported configuration. Useful for debugging, for example to bypass rhg if the default hg points to rhg.

Note that because this requires loading the configuration, it is possible that rhg errors out before being able to fall back. 😭

ignored-extensions — controls which extensions should be ignored by rhg. By default, rhg triggers the rhg.on-unsupported behavior on any unsupported extensions. Users can disable that behavior when they know that a given extension does not need support from rhg.

Expects a list of extension names, or * to ignore all extensions.

Note: *:<suboption> is also a valid extension name for this configuration option. As of this writing, the only valid "global" suboption is required.

on-unsupported — controls the behavior of rhg when detecting unsupported features.

Possible values are abort (default), abort-silent and fallback.

abort — print an error message describing what feature is not supported, and exit with code 252.
abort-silent — silently exit with code 252.
fallback — try running the fallback executable with the same parameters (and trace the fallback reason, use RUST_LOG=trace to see).

safe-mismatch.source-safe — controls what happens when the shared repository does not use the share-safe mechanism but its source repository does.

Possible values are abort (default), allow, upgrade-abort and upgrade-allow.

abort — disallows running any command and aborts.
allow — respects the feature presence in the share source.
upgrade-abort — tries to upgrade the share to use share-safe; if it fails, aborts.
upgrade-allow — tries to upgrade the share; if it fails, continue by respecting the share source setting.

Check hg help config.format.use-share-safe for details about the share-safe feature.

safe-mismatch.source-safe:verbose-upgrade — display a message when upgrading. (default: True)
safe-mismatch.source-safe.warn — shows a warning on operations if the shared repository does not use share-safe, but the source repository does. (default: True)
safe-mismatch.source-not-safe — controls what happens when the shared repository uses the share-safe mechanism but its source does not.

Possible values are abort (default), allow, downgrade-abort and downgrade-allow.

abort — disallows running any command and aborts.
allow — respects the feature presence in the share source.
downgrade-abort — tries to downgrade the share to not use share-safe; if it fails, aborts.
downgrade-allow — tries to downgrade the share to not use share-safe; if it fails, continue by respecting the shared source setting.

Check hg help config.format.use-share-safe for details about the share-safe feature.

safe-mismatch.source-not-safe:verbose-upgrade — display a message when upgrading. (default: True)
safe-mismatch.source-not-safe.warn — shows a warning on operations if the shared repository uses share-safe, but the source repository does not. (default: True)

📦 storage 📦

Control the strategy Mercurial uses internally to store history. Options in this category impact performance and repository size. No pressure or anything. 👑

all-slow-path — control the behavior of Mercurial when lacking performant code.

Some format features might only have a fast implementation when a specific flavor is installed (e.g. when the Rust extensions are available). A slow pure Python implementation might be available to help with converting the repository to another format or to perform a few accesses in an automation context. Using such accesses might result in Mercurial becoming multiple time slower than usual.

Acceptable values:

allow: silently use the slower implementation to access the repository.
warn: warn, but use the slower implementation to access the repository.
abort: prevent access to such repositories. (This is the default)

See the individual storage.*.slow-path configs for details. These options can override the default.

revlog.dirstate-v2.slow-path — control the behavior of Mercurial when using a repository with the "dirstate-v2" feature with an installation of Mercurial without a fast implementation for the feature:
- allow: silently use the slower implementation to access the repository.
- warn: warn, but use the slower implementation to access the repository.
- default: use value from the storage.all-slow-path value.
- abort: prevent access to such repositories. (This is the default)

For details on the "dirstate-v2" feature, see: hg help config.format.use-dirstate-v2.

revlog.exchange-compressed-delta — controls whether the repository might emit or request compressed deltas in bundles.

Exchanging deltas in their compressed form results in larger bundles and higher bandwidth usage, but reduces CPU usage on both ends and helps the main server to use aggressive compression levels to share that benefit with ordinary clients pulling from them.

Even when activated, the exchange of compressed deltas will only be used if the exchange uses a changegroup format that supports it (04 and above) and the receiving end supports it.

revlog.issue6528.fix-incoming — version 5.8 of Mercurial had a bug leading to altering the parent of file revision with copy information (or any other metadata) on exchange. This leads to the copy metadata to be overlooked by various internal logic. The issue was fixed in Mercurial 5.8.1. (See https://bz.mercurial-scm.org/show_bug.cgi?id=6528 for details.)

As a result Mercurial is now checking and fixing incoming file revisions to make sure there parents are in the right order. This behavior can be disabled by setting this option to no. This apply to revisions added through push, pull, clone and unbundle.

To fix affected revisions that already exist within the repository, one can use hg debug-repair-issue-6528.

revlog.delta-parent-search.candidate-group-chunk-size — tune the number of delta bases the storage will consider in the same "round" of search. In some very rare cases, using a smaller value might result in faster processing at the possible expense of storage space, while using larger values might result in slower processing at the possible benefit of storage space. A value of "0" means no limitation.

default: no limitation

This is unlikely that you'll have to tune this configuration. If you think you do, consider talking with the mercurial developer community about your repositories. 🫶

revlog.mmap.index — whether to use the Operating System "memory mapping" feature (when possible) to access the revlog index. This improves performance and reduces memory pressure.
revlog.mmap.index:size-threshold — the size of index above which to use the "memory mapping" feature.
revlog.optimize-delta-parent-choice — when storing a merge revision, both parents will be equally considered as a possible delta base. This results in better delta selection and improved revlog compression. This option is enabled by default.

Turning this option off can result in large increase of repository size for repository with many merges.

revlog.persistent-nodemap.mmap

Whether to use the Operating System "memory mapping" feature (when possible) to access the persistent nodemap data. This improve performance and reduce memory pressure.

Default to True.

For details on the "persistent-nodemap" feature, see: hg help config.format.use-persistent-nodemap.

okay so this one's just letting the OS do its "memory mapping" thing (whenever it can) so it can get at your persistent nodemap data. it's giving performance glow-up ✨ and way less memory pressure. default? True 💖 and for the full tea on the "persistent-nodemap" feature, go run hg help config.format.use-persistent-nodemap.

revlog.persistent-nodemap.slow-path — controls what Mercurial does when you're using a repo with a "persistent" nodemap, but your Mercurial install has no fast implementation of that feature. the vibes:
- allow: silently use the slower implementation to access the repo.
- warn: warn, but use the slower implementation to access the repo.
- default: use the value from the storage.all-slow-path value.
- abort: prevent access to such repositories. (this is the default)

for details on the "persistent-nodemap" feature, see: hg help config.format.use-persistent-nodemap.

revlog.reuse-external-delta-parent — controls the order in which delta parents are considered when adding new revisions from an external source. (typically: apply bundle from hg pull or hg push).

new revisions are usually provided as a delta against other revisions. by default, Mercurial will try to reuse this delta first, therefore using the same "delta parent" as the source. directly using delta's from the source reduces CPU usage and usually speeds up operation. however, in some case, the source might have sub-optimal delta bases and forcing their reevaluation is useful. for example, pushes from an old client could have sub-optimal delta's parent that the server want to optimize. (lack of general delta, bad parents, choice, lack of sparse-revlog, etc).

this option is enabled by default. turning it off will ensure bad delta parent choices from older client do not propagate to this repository, at the cost of a small increase in CPU consumption.

Note: this option only control the order in which delta parents are considered. Even when disabled, the existing delta from the source will be reused if the same delta parent is selected.

revlog.reuse-external-delta — controls the reuse of delta from external source. (typically: apply bundle from hg pull or hg push).

new revisions are usually provided as a delta against another revision. by default, Mercurial will not recompute the same delta again, trusting externally provided deltas. there have been rare cases of small adjustment to the diffing algorithm in the past. so in some rare case, recomputing delta provided by ancient clients can provides better results. disabling this option means going through a full delta recomputation for all incoming revisions. it means a large increase in CPU usage and will slow operations down. 😭

this option is enabled by default. when disabled, it also disables the related storage.revlog.reuse-external-delta-parent option.

revlog.reuse-external-delta-compression — when true, reuse the compression of incoming deltas when receiving a compressed delta if its compression type is compatible with the one used by the revlog. 🫶
revlog.zlib.level — zlib compression level used when storing data into the repository. accepted Value range from 1 (lowest compression) to 9 (highest compression). Zlib default value is 6.
revlog.zstd.level — zstd compression level used when storing data into the repository. accepted Value range from 1 (lowest compression) to 22 (highest compression). (default 3)

server 🖥️

Controls generic server settings. the whole server vibe check, bestie.

bookmarks-pushkey-compat — trigger pushkey hook when being pushed bookmark updates. this config exist for compatibility purpose (default to True).

if you use pushkey and pre-pushkey hooks to control bookmark movement we recommend you migrate them to txnclose-bookmark and pretxnclose-bookmark. 👑

compressionengines — list of compression engines and their relative priority to advertise to clients.

the order of compression engines determines their priority, the first having the highest priority. if a compression engine is not listed here, it won't be advertised to clients.

if not set (the default), built-in defaults are used. run hg debuginstall to list available compression engines and their default wire protocol priority.

older Mercurial clients only support zlib compression and this setting has no effect for legacy clients.

uncompressed — whether to allow clients to clone a repository using the uncompressed streaming protocol. this transfers about 40% more data than a regular clone, but uses less memory and CPU on both server and client. over a LAN (100 Mbps or better) or a very fast WAN, an uncompressed streaming clone is a lot faster (~10x) than a regular clone. over most WAN connections (anything slower than about 6 Mbps), uncompressed streaming is slower, because of the extra data transfer overhead. this mode will also temporarily hold the write lock while determining what data to transfer. (default: True)
uncompressedallowsecret — whether to allow stream clones when the repository contains secret changesets. (default: False)
preferuncompressed — when set, clients will try to use the uncompressed streaming protocol. (default: False)
disablefullbundle — when set, servers will refuse attempts to do pull-based clones. if this option is set, preferuncompressed and/or clone bundles are highly recommended. partial clones will still be allowed. (default: False)
streamunbundle — when set, servers will apply data sent from the client directly, otherwise it will be written to a temporary file first. this option effectively prevents concurrent pushes.
pullbundle — when set, the server will check pullbundles.manifest for bundles covering the requested heads and common nodes. the first matching entry will be streamed to the client.

for HTTP transport, the stream will still use zlib compression for older clients.

concurrent-push-mode — level of allowed race condition between two pushing clients. 🏁
- 'strict': push is abort if another client touched the repository while the push was preparing.
- 'check-related': push is only aborted if it affects head that got also affected while the push was preparing. (default since 5.4)

'check-related' only takes effect for compatible clients (version 4.3 and later). older clients will use 'strict'.

validate — whether to validate the completeness of pushed changesets by checking that all new file revisions specified in manifests are present. (default: False)
maxhttpheaderlen — instruct HTTP clients not to send request headers longer than this many bytes. (default: 1024)
bundle1 — whether to allow clients to push and pull using the legacy bundle1 exchange format. (default: True)
bundle1gd — like bundle1 but only used if the repository is using the generaldelta storage format. (default: True)
bundle1.push — whether to allow clients to push using the legacy bundle1 exchange format. (default: True)
bundle1gd.push — like bundle1.push but only used if the repository is using the generaldelta storage format. (default: True)
bundle1.pull — whether to allow clients to pull using the legacy bundle1 exchange format. (default: True)
bundle1gd.pull — like bundle1.pull but only used if the repository is using the generaldelta storage format. (default: True)

large repositories using the generaldelta storage format should consider setting this option because converting generaldelta repositories to the exchange format required by the bundle1 data format can consume a lot of CPU. 🔥

bundle2.stream — whether to allow clients to pull using the bundle2 streaming protocol. (default: True)
zliblevel — integer between -1 and 9 that controls the zlib compression level for wire protocol commands that send zlib compressed output (notably the commands that send repository history data).

the default (-1) uses the default zlib compression level, which is likely equivalent to 6. 0 means no compression. 9 means maximum compression.

setting this option allows server operators to make trade-offs between bandwidth and CPU used. lowering the compression lowers CPU utilization but sends more bytes to clients.

this option only impacts the HTTP server.

zstdlevel — integer between 1 and 22 that controls the zstd compression level for wire protocol commands. 1 is the minimal amount of compression and 22 is the highest amount of compression.

the default (3) should be significantly faster than zlib while likely delivering better compression ratios. ✨

this option only impacts the HTTP server.

smtp 📧

Configuration for extensions that need to send email messages. yes bestie, your extensions can send mail, we're that iconic 💅

host — host name of mail server, e.g. "mail.example.com".
port — optional. port to connect to on mail server. (default: 465 if tls is smtps; 25 otherwise)
tls — optional. method to enable TLS when connecting to mail server: starttls, smtps or none. (default: none)
username — optional. user name for authenticating with the SMTP server. (default: None)
password — optional. password for authenticating with the SMTP server. if not specified, interactive sessions will prompt the user for a password; non-interactive sessions will fail. (default: None)
local_hostname — optional. the hostname that the sender can use to identify itself to the MTA.

subpaths Subrepository source URLs can go stale if a remote server changes name or becomes temporarily unavailable. This section lets you define rewrite rules of the form:

where pattern is a regular expression matching a subrepository source URL and replacement is the replacement string used to rewrite it. Groups can be matched in pattern and referenced in replacements. For instance:

http://server/(.*)-hg/ = http://hg.server/\1/

rewrites http://server/foo-hg/ into http://hg.server/foo/.

Relative subrepository paths are first made absolute, and the rewrite rules are then applied on the full (absolute) path. If pattern doesn't match the full path, an attempt is made to apply it on the relative path alone. The rules are applied in definition order.

subrepos This section contains options that control the behavior of the subrepositories feature. See also hg help subrepos.

Security note: auditing in Mercurial is known to be insufficient to prevent clone-time code execution with carefully constructed Git subrepos. It is unknown if a similar detect is present in Subversion subrepos. Both Git and Subversion subrepos are disabled by default out of security concerns. These subrepo types can be enabled using the respective options below.

allowed

Whether subrepositories are allowed in the working directory.

When false, commands involving subrepositories (like hg update) will fail for all subrepository types. (default: true)

hg:allowed

Whether Mercurial subrepositories are allowed in the working directory. This option only has an effect if subrepos.allowed is true. (default: true)

git:allowed

Whether Git subrepositories are allowed in the working directory. This option only has an effect if subrepos.allowed is true.

See the security note above before enabling Git subrepos. (default: false)

svn:allowed

Whether Subversion subrepositories are allowed in the working directory. This option only has an effect if subrepos.allowed is true.

See the security note above before enabling Subversion subrepos. (default: false)

templatealias Alias definitions for templates. See hg help templates for details.

templates Use the [templates] section to define template strings. See hg help templates for details.

trusted Mercurial will not use the settings in the .hg/hgrc file from a repository if it doesn't belong to a trusted user or to a trusted group, as various hgrc features allow arbitrary commands to be run. This issue is often encountered when configuring hooks or extensions for shared repositories or servers. However, the web interface will use some safe settings from the [web] section.

This section specifies what users and groups are trusted. The current user is always trusted. To trust everybody, list a user or a group with name *. These settings must be placed in an already-trusted file to take effect, such as $HOME/.hgrc of the user or service running Mercurial.

users

Comma-separated list of trusted users.

groups

Comma-separated list of trusted groups.

ui User interface controls.

archivemeta

Whether to include the .hg_archival.txt file containing meta data (hashes for the repository base and for tip) in archives created by the hg archive command or downloaded via hgweb. (default: True)

askusername

Whether to prompt for a username when committing. If True, and neither $HGUSER nor $EMAIL has been specified, then the user will be prompted to enter a username. If no username is entered, the default USER@HOST is used instead. (default: False)

clonebundles

Whether the "clone bundles" feature is enabled.

When enabled, hg clone may download and apply a server-advertised bundle file from a URL instead of using the normal exchange mechanism.

This can likely result in faster and more reliable clones.

(default: True)

clonebundlefallback

Whether failure to apply an advertised "clone bundle" from a server should result in fallback to a regular clone.

This is disabled by default because servers advertising "clone bundles" often do so to reduce server load. If advertised bundles start mass failing and clients automatically fall back to a regular clone, this would add significant and unexpected load to the server since the server is expecting clone operations to be offloaded to pre-generated bundles. Failing fast (the default behavior) ensures clients don't overwhelm the server when "clone bundle" application fails.

(default: False)

clonebundleprefers

Defines preferences for which "clone bundles" to use.

Servers advertising "clone bundles" may advertise multiple available bundles. Each bundle may have different attributes, such as the bundle type and compression format. This option is used to prefer a particular bundle over another.

The following keys are defined by Mercurial:

BUNDLESPEC A bundle type specifier. These are strings passed to hg bundle -t. e.g. gzip-v2 or bzip2-v1.

COMPRESSION The compression format of the bundle. e.g. gzip and bzip2.

Server operators may define custom keys.

Example values: COMPRESSION=bzip2, BUNDLESPEC=gzip-v2, COMPRESSION=gzip.

By default, the first bundle advertised by the server is used.

color

When to colorize output. Possible value are Boolean ("yes" or "no"), or "debug", or "always". (default: "yes"). "yes" will use color whenever it seems possible. See hg help color for details.

commitsubrepos

Whether to commit modified subrepositories when committing the parent repository. If False and one subrepository has uncommitted changes, abort the commit. (default: False)

debug

Print debugging information. (default: False)

editor

The editor to use during a commit. (default: $EDITOR or vi)

fallbackencoding

Encoding to try if it's not possible to decode the changelog using UTF-8. (default: ISO-8859-1)

graphnodetemplate

(DEPRECATED) Use command-templates.graphnode instead.

ignore

A file to read per-user ignore patterns from. This file should be in the same format as a repository-wide .hgignore file. Filenames are relative to the repository root. This option supports hook syntax, so if you want to specify multiple ignore files, you can do so by setting something like ignore.other = ~/.hgignore2. For details of the ignore file format, see the hgignore(5) man page.

interactive

Allow to prompt the user. (default: True)

interface

Select the default interface for interactive features (default: text). Possible values are 'text' and 'curses'.

interface.chunkselector

Select the interface for change recording (e.g. hg commit -i). Possible values are 'text' and 'curses'. This config overrides the interface specified by ui.interface.

large-file-limit

Largest file size that gives no memory use warning. Possible values are integers or 0 to disable the check. Value is expressed in bytes by default, one can use standard units for convenience (e.g. 10MB, 0.1GB, etc) (default: 10MB)

logtemplate

(DEPRECATED) Use command-templates.log instead.

merge

The conflict resolution program to use during a manual merge. For more information on merge tools see hg help merge-tools. For configuring merge tools see the [merge-tools] section.

mergemarkers

Sets the merge conflict marker label styling. The detailed style uses the command-templates.mergemarker setting to style the labels. The basic style just uses 'local' and 'other' as the marker label. One of basic or detailed. (default: basic)

mergemarkertemplate

(DEPRECATED) Use command-templates.mergemarker instead.

message-output

Where to write status and error messages. (default: stdio)

channel

Use separate channel for structured output. (Command-server only)

stderr

Everything to stderr.

stdio

Status to stdout, and error to stderr.

origbackuppath

The path to a directory used to store generated .orig files. If the path is not a directory, one will be created. If set, files stored in this directory have the same name as the original file and do not have a .orig suffix.

paginate

Control the pagination of command output (default: True). See hg help pager for details.

patch

An optional external tool that hg import and some extensions will use for applying patches. By default Mercurial uses an internal patch utility. The external tool must work as the common Unix patch program. In particular, it must accept a -p argument to strip patch headers, a -d argument to specify the current directory, a file name to patch, and a patch file to take from stdin.

It is possible to specify a patch tool together with extra arguments. For example, setting this option to patch --merge will use the patch program with its 2-way merge option.

portablefilenames

Check for portable filenames. Can be warn, ignore or abort. (default: warn)

warn

Print a warning message on POSIX platforms, if a file with a non-portable filename is added (e.g. a file with a name that can't be created on Windows because it contains reserved parts like AUX, reserved characters like :, or would cause a case collision with an existing file).

ignore

Don't print a warning.

abort

The command is aborted.

true

Alias for warn.

false

Alias for ignore.

On Windows, this configuration option is ignored and the command aborted.

pre-merge-tool-output-template

(DEPRECATED) Use command-template.pre-merge-tool-output instead.

quiet

Reduce the amount of output printed. (default: False)

relative-paths

Prefer relative paths in the UI.

remotecmd

report_untrusted — no wait, let me not bullet these, they've got too much to say. Keep reading bestie, it's all here 💖

report_untrusted

Warn you if a .hg/hgrc file gets ignored because it isn't owned by a trusted user or group. (default: True)

slash

(Deprecated. Use the slashpath template filter instead.) Displays paths using a slash (/) as the path separator. Honestly this only matters on systems where the default separator isn't slash — like Windows, which uses the backslash character (\). (default: False)

statuscopies

Shows copies in the status command.

ssh

The command used for SSH connections. (default: ssh)

ssherrorhint

A hint shown to the user when an SSH error happens (e.g. Please see http://company/internalwiki/ssh.html).

strict

Demands exact command names instead of letting you use unambiguous abbreviations. (default: False)

style

Name of the style to use for command output.

supportcontact

A URL where users should report a Mercurial traceback. Use this if you're a big organisation with your own Mercurial deployment process and crash reports need to go to your internal support instead. 🫶

textwidth

Maximum width of help text. A longer line generated by hg help or hg subcommand --help gets broken after white space to hit this width — or the terminal width, whichever comes first. A non-positive value disables this and the terminal width gets used instead. (default: 78)

timeout

The timeout used when a lock is held, in seconds. A negative value means no timeout. (default: 600)

timeout.warn

Time (in seconds) before a warning gets printed about a held lock. A negative value means no warning. (default: 0)

traceback

Mercurial always prints a traceback when an unknown exception occurs. Setting this to True makes Mercurial print a traceback on all exceptions, even the ones it already recognises (like IOError or MemoryError). (default: False)

tweakdefaults

So by default Mercurial's behaviour changes very little from release to release, but over time the recommended config settings shift. Turn this on to opt in and get automatic tweaks to Mercurial's behaviour as time goes on. Heads up tho: this setting does nothing if HGPLAIN is set, or if HGPLAINEXCEPT is set and doesn't include tweakdefaults. (default: False)

Right now it means:

[ui]
# The rollback command is dangerous. As a rule, don't use it.
rollback = False
# Make `hg status` report copy information
statuscopies = yes
# Prefer curses UIs when available. Revert to plain-text with `text`.
interface = curses
# Make compatible commands emit cwd-relative paths by default.
relative-paths = yes

[commands]
# Grep working directory by default.
grep.all-files = True
# Refuse to perform an `hg update` that would cause a file content merge
update.check = noconflict
# Show conflicts information in `hg status`
status.verbose = True
# Make `hg resolve` with no action (like `-m`) fail instead of re-merging.
resolve.explicit-re-merge = True

[diff]
git = 1
showfunc = 1
word-diff = 1

username

The committer of a changeset created when running commit. Typically a person's name and email address, e.g. Fred Widget <fred@example.com>. Environment variables inside the username get expanded. ✨

(default: $EMAIL or username@hostname. If the username in hgrc is empty — like if the system admin set username = in the system hgrc — then it has to be specified manually or in a different hgrc file)

verbose

Increases the amount of output printed. (default: False)

✨ usage ✨

repository-role

What this repository is used for.

This gets used to adjust behaviour and performance so everything best fits the repository's purpose.