OPAM-CLEAN(1)

📦
version 2.6.1 · 8 versions
, in arch rolling, fedora 44

🌸 OPAM-CLEAN(1) 🌸

okay so this is opam-clean, straight out of the Opam Manual, and bestie it is exactly the page you want when your disk is full and you're like "why is this folder 40GB" 💀

✨ NAME ✨

opam-clean — cleans up opam caches 🧼✨

🫧 SYNOPSIS 🫧

opam clean [OPTION]…

💖 DESCRIPTION 💖

So basically: opam clean cleans up your opam caches and reclaims some disk space, which is giving "spring cleaning but for your ~/.opam folder" 🧹🦋

And here's the tea you actually need to know — if you specify no options at all, the default is:

--logs --download-cache --switch-cleanup

so it's not just sitting there doing nothing, she came ready. 👑

🎀 OPTIONS 🎀

  • -a, --all-switches — run the switch cleanup commands in all switches. This implies --switch-cleanup, so yeah, that one's coming along for the ride too. 🚗💨
  • -c, --download-cache — clear the cache of downloaded files (that's $OPAMROOT/download-cache, iykyk), and also the obsolete $OPAMROOT/archives, if that exists. Old archives, we don't know her anymore 💅
  • --dry-run — print the removal commands like a lil preview reel, but don't execute them. Main character move for the cautious girlies 🙈
  • --logs — clear the logs directory. bye bye receipts ✨
  • -r, --repo-cache — clear the repository cache. It will be rebuilt by the next opam command that needs it, so like, it comes back. She's resilient. 🌱
  • -s, --switch-cleanup — run the switch-specific cleanup: clears backups, build dirs, uncompressed package sources of non-dev packages, local metadata of previously pinned packages, etc. the whole under-the-bed situation, gone 🧺
  • --untracked — clean untracked file and directories 🫧
  • --unused-repositories — clear any configured repository that is not used by any switch nor the default. if nobody's using her, she doesn't get to live in your config rent-free 💀

🫶 COMMON OPTIONS 🫶

These options are common to all commands — so like, the shared group-chat of opam flags 📱

  • --best-effort — don't fail if all requested packages can't be installed: try to install as many as possible. Note that not all external solvers may support this option (recent versions of aspcud or mccs should). This is equivalent to setting $OPAMBESTEFFORT environment variable. lowkey "we tried our best and that's enough" energy 🥺
  • --cli=MAJOR.MINOR (absent=2.6) — use the command-line interface syntax and semantics of MAJOR.MINOR. Intended for any persistent use of opam (scripts, blog posts, etc.), any version of opam in the same MAJOR series will behave as for the specified MINOR release. The flag was not available in opam 2.0, so to select the 2.0 CLI, set the OPAMCLI environment variable to 2.0 instead of using this parameter. ⏳
  • --color=WHEN — colorize the output. WHEN must be one of always, never or auto. 🌈
  • --confirm-level=LEVEL — confirmation level, LEVEL must be one of ask, no, yes or unsafe-yes. Can be specified more than once. If --yes or --no are also given, the value of the last --confirm-level is taken into account. This is equivalent to setting $OPAMCONFIRMLEVEL. 🫡
  • --criteria=CRITERIA — specify user preferences for dependency solving for this run. Overrides $OPAMCRITERIA, $OPAMFIXUPCRITERIA and $OPAMUPGRADECRITERIA. For details on the supported language, and the external solvers available, see http://opam.ocaml.org/doc/External_solvers.html. A general guide to using solver preferences can be found at http://www.dicosmo.org/Articles/usercriteria.pdf. 📚
  • --cudf=FILENAME — debug option: Save the CUDF requests sent to the solver to FILENAME-<n>.cudf where <n> is the n-th call to the solver during the opam run. 🐛
  • --debug — print debug message to stderr. This is equivalent to setting $OPAMDEBUG to "true". 🔍
  • --debug-level=LEVEL — like --debug, but allows specifying the debug level (--debug sets it to 1). Equivalent to setting $OPAMDEBUG to a positive integer. 📈
  • --git-version — print the git version of opam, if set (i.e. you are using a development version), and exit. 🐙
  • --help[=FMT] (default=auto) — show this help in format FMT. The value FMT must be one of auto, pager, groff or plain. With auto, the format is pager or plain whenever the TERM env var is dumb or undefined. 🙋‍♀️
  • --ignore-pin-depends — ignore extra pins required by packages that get pinned, either manually through opam pin or through opam install DIR. This is equivalent to setting IGNOREPINDEPENDS=true. 🙅‍♀️
  • --json=FILENAME — save the results of the opam run in a computer-readable file. If the filename contains the character %, it will be replaced by an index that doesn't overwrite an existing file. Similar to setting the $OPAMJSON variable. 🤖
  • --no — answer no to all opam yes/no questions without prompting. See also --confirm-level. This is equivalent to setting $OPAMNO to "true". 🚫
  • --no-aspcud — Removed in 2.1. 💀 she's gone, don't look for her
  • --no-auto-upgrade — when configuring or updating a repository that is written for an earlier opam version (1.2), opam internally converts it to the current format. This disables this behaviour. Note that repositories should define their format version in a 'repo' file at their root, or they will be assumed to be in the older format. It is, in any case, preferable to upgrade the repositories manually using opam admin upgrade [--mirror URL] when possible. 🕰️
  • --no-self-upgrade — opam will replace itself with a newer binary found at OPAMROOT/opam if present. This disables this behaviour. 🛑
  • -q, --quiet — disables --verbose. 🤫
  • --root=ROOT — use ROOT as the current root path. This is equivalent to setting $OPAMROOT to ROOT. 🏠
  • --safe, --readonly — make sure nothing will be automatically updated or rewritten. Useful for calling from completion scripts, for example. Will fail whenever such an operation is needed ; also avoids waiting for locks, skips interactive questions and overrides the $OPAMDEBUG variable. This is equivalent to set environment variable $OPAMSAFE. 🔒
careful babe — this one will fail whenever such an operation is needed. that's not a bug, that's the whole point.
  • --solver=CMD — specify the CUDF solver to use for resolving package installation problems. This is either a predefined solver (this version of opam supports builtin-mccs+lp(), builtin-mccs+glpk, builtin-dummy-z3-solver, builtin-0install, aspcud, mccs, aspcud-old, packup), or a custom command that should contain the variables %{input}%, %{output}%, %{criteria}%, and optionally %{timeout}%. This is equivalent to setting $OPAMEXTERNALSOLVER. 🧠
  • --strict — fail whenever an error is found in a package definition or a configuration file. The default is to continue silently if possible. 😤
  • --switch=SWITCH — use SWITCH as the current compiler switch. This is equivalent to setting $OPAMSWITCH to SWITCH. 🎚️
  • --use-internal-solver — disable any external solver, and use the built-in one (this requires that opam has been compiled with a built-in solver). This is equivalent to setting $OPAMNOASPCUD or $OPAMUSEINTERNALSOLVER. 🛠️
  • -v, --verbose — be more verbose. One -v shows all package commands, repeat to also display commands called internally (e.g. tar, curl, patch etc.) Repeating n times is equivalent to setting $OPAMVERBOSE to "n". 🗣️
  • --version — show version information. 🏷️
  • -w, --working-dir — whenever updating packages that are bound to a local, version-controlled directory, update to the current working state of their source instead of the last committed state, or the ref they are pointing to. As source directory is copied as it is, if it isn't clean it may result on a opam build failure. This only affects packages explicitly listed on the command-line. It can also be set with $OPAMWORKINGDIR. 💻
  • -y, --yes — answer yes to all opam yes/no questions without prompting. See also --confirm-level. This is equivalent to setting $OPAMYES to "true". ✅

🌍 ENVIRONMENT 💖

opam is lowkey obsessed with environment variables, bestie, and this is the full roster. Set them and opam listens, no cap.

Quick note before we dive in: all the boolean ones take the same lil vocabulary of vibes — set them to "0", "no", "false" or just the empty string to disable them, and "1", "yes" or "true" to enable them. Pick your fighter, they all work. 🎀

  • OPAMALLPARENS — surrounds all filters with parenthesis. yeah. all of them. parenthesise everything bestie.
  • OPAMASSUMEDEPEXTS — see option --assume-depexts.
  • OPAMAUTOANSWER — internal use only, nothing to see here, mind your business 🙈
  • OPAMAUTOREMOVE — see the remove option --auto-remove.
  • OPAMBESTEFFORT — see option --best-effort.
  • OPAMBESTEFFORTPREFIXCRITERIA — sets the string that must be prepended to the criteria when the --best-effort option is set, and it's expected to maximise the opam-query property in the solution. the way it just patches the criteria… 💅
  • OPAMBUILDDOC — removed in 2.1. rest in peace icon 💀
  • OPAMBUILDTEST — removed in 2.1. also gone, also missed.
  • OPAMCLI — see option --cli.
  • OPAMCOLOR — when set to always or never, sets a default value for the --color option.
  • OPAMCONFIRMLEVEL — see option --confirm-level. and know this: OPAMCONFIRMLEVEL has priority over OPAMYES and OPAMNO. it's the main character, everyone else waits their turn 👑
  • OPAMCRITERIA — specifies user preferences for dependency solving. the default value depends on the solver version, so run config report to know the current setting. see also option --criteria.
  • OPAMCUDFFILE — saves the cudf graph to the file file-actions-explicit.dot. dot file bestie!!
  • OPAMCUDFTRIM — controls the filtering of unrelated packages during CUDF preprocessing.
  • OPAMCURL — can be used to select a given curl program. see OPAMFETCH for more options.
  • OPAMDEBUG — see options --debug and --debug-level.
  • OPAMDEBUGSECTIONS — if set, limits debug messages to the space-separated list of sections. sections can optionally have a specific debug level (for example, CLIENT:2 or CLIENT CUDF:2), but otherwise use --debug-level.
  • OPAMDIGDEPTH — defines how aggressive the lookup for conflicts during CUDF preprocessing is. how deep are we digging? yes 🕳️
  • OPAMDOWNLOADJOBS — sets the maximum number of simultaneous downloads.
  • OPAMDROPWORKINGDIR — overrides packages previously updated with --working-dir on update. without this variable set, opam would keep them unchanged unless explicitly named on the command-line.
  • OPAMDRYRUN — see option --dry-run.
  • OPAMEDITOR — sets the editor to use for opam file editing, and it overrides $EDITOR and $VISUAL. yeah it goes over their heads, sorry 🫶
  • OPAMERRLOGLEN — sets the number of log lines printed when a sub-process fails. 0 prints all of them. all. every single line. good luck 💀
  • OPAMEXTERNALSOLVER — see option --solver.
  • OPAMFAKE — see option --fake.
  • OPAMFETCH — specifies how to download files: either wget, curl, or a custom command where the variables %{url}%, %{out}%, %{retry}%, %{compress}% and %{checksum}% will be replaced. overrides the download-command value from the main config file.
  • OPAMFIXUPCRITERIA — same as OPAMUPGRADECRITERIA, but specific to fixup and reinstall.
  • OPAMIGNOREAVAILABLE — see the install option --ignore-available-on.
  • OPAMIGNORECONSTRAINTS — see the install option --ignore-constraints-on.
  • OPAMIGNOREPINDEPENDS — see option --ignore-pin-depends.
  • OPAMINPLACEBUILD — see option --inplace-build.
  • OPAMJOBS — sets the maximum number of parallel workers to run. we love a little multitasking moment ✨
  • OPAMJSON — log json output to the given file (use the character % to index the files).
  • OPAMKEEPBUILDDIR — see the install option --keep-build-dir.
  • OPAMKEEPLOGS — tells opam to not remove some temporary command logs and some backups. this skips some finalisers and may also help to get more reliable backtraces.
  • OPAMLOCKED — a combination of the --locked and --lock-suffix options.
  • OPAMLOGS — logdir sets the log directory; the default is a temporary directory in /tmp.
  • OPAMMAKECMD — set the system make command to use.
  • OPAMMERGEOUT — merge process outputs, with stderr going on stdout.
  • OPAMNO — answer no to any question asked, see options --no and --confirm-level. OPAMNO is ignored if either OPAMCONFIRMLEVEL or OPAMYES is set. it knows its place, it's not fighting anybody 😭
  • OPAMNOAGGREGATE — with opam admin check, don't aggregate packages.
  • OPAMNOASPCUD — deprecated. don't use it, it's giving vintage for no reason.
  • OPAMNOAUTOUPGRADE — disables automatic internal upgrade of repositories in an earlier format to the current one, on update or init.
  • OPAMNOCHECKSUMS — enables the option --no-checksums when available.
  • OPAMNODEPEXTS — disables system dependencies handling, see option --no-depexts.
  • OPAMNOENVNOTICE — internal.
  • OPAMNOSELFUPGRADE — see option --no-self-upgrade.
  • OPAMPINKINDAUTO — sets whether version control systems should be detected when pinning to a local path. enabled by default since 1.3.0.
  • OPAMPRECISETRACKING — fine grain tracking of directories. 🔍
  • OPAMPREPRO — set this to false to disable CUDF preprocessing. it's less efficient, but it might help debugging solver issue.
  • OPAMREPOSITORYTARRING — internally store all non-vcs repositories as tar.gz files (by default, http repositories are stored as archive). this can be much faster on filesystems that don't cope well with scanning large trees. all operations are done in-memory, no I/O for scanning the repository. it's giving speed, it's giving elegance ✨
  • OPAMREQUIRECHECKSUMS — enables the option --require-checksums when available (e.g. for opam install).
  • OPAMRETRIES — sets the number of tries before failing downloads.
  • OPAMREUSEBUILDDIR — see option --reuse-build-dir.
  • OPAMROOT — see option --root. this is automatically set by opam env --root=DIR --set-root.
  • OPAMROOTISOK — don't complain when running as root.
  • OPAMSAFE — see option --safe.
  • OPAMSHOW — see option --show.
  • OPAMSKIPUPDATE — see option --skip-updates.
  • OPAMSKIPVERSIONCHECKS — bypasses some version checks. unsafe, for compatibility testing only. seriously bestie, testing only, do not make this your personality 🚨
  • OPAMSOLVERALLOWSUBOPTIMAL — (default true) allows some solvers to still return a solution when they reach timeout; while the solution remains assured to be consistent, there is no guarantee in this case that it fits the expected optimisation criteria. if true, opam will continue with a warning; if false, a timeout is an error. currently only the builtin-z3 backend handles this degraded case.
  • OPAMSOLVERTIMEOUT — change the time allowance of the solver. default is 60.0, set to 0 for unlimited. note that all solvers may not support this option.
  • OPAMSOLVERTOLERANCE — changes the tolerance towards the solver choosing an unoptimized solution (i.e. it might pull outdated packages 👀). typical values range from 0.0 (best solution known to the solver) to 1.0 (unoptimized solution). default is 0.0. this option is useful in case the solver can't find a solution in a reasonable time (see $OPAMSOLVERTIMEOUT). note that all solvers may not support this option.
  • OPAMSTATS — removed in 2.4. gone but not forgotten 🕊️
  • OPAMSTATUSLINE — display a dynamic status line showing what's currently going on on the terminal. (one of always, never or auto)
  • OPAMSTRICT — fail on inconsistencies (file reading, switch import, etc.). no chaos tolerated, periodt.
  • OPAMSWITCH — see option --switch. automatically set by opam env --switch=SWITCH --set-switch.
  • OPAMUNLOCKBASE — see the install option --unlock-base.
  • OPAMUPGRADECRITERIA — specifies user preferences for dependency solving when performing an upgrade. it overrides OPAMCRITERIA in upgrades if both are set. see also option --criteria.
  • OPAMUSEINTERNALSOLVER — see option --use-internal-solver.
  • OPAMUSEOPENSSL — removed in 2.2. bye bye 💅
  • OPAMUTF8 — use UTF8 characters in output (one of always, never or auto). by default it's auto, which is determined from the locale.
  • OPAMUTF8MSGS — use extended UTF8 characters (camels 🐪) in opam messages. implies OPAMUTF8. this is set by default on macOS only.
  • OPAMVALIDATIONHOOK — if set, uses the %{hook}% command to validate an opam repository update.
  • OPAMVERBOSE — see option --verbose.
  • OPAMVERBOSEON — see option --verbose-on.
  • OPAMVERSIONLAGPOWER — do not use. that's it, that's the whole description, do not use it 🙅‍♀️
  • OPAMWITHDEVSETUP — see the install option --with-dev-setup.
  • OPAMWITHDOC — see the install option --with-doc.
  • OPAMWITHTEST — see the install option --with-test.
  • OPAMWORKINGDIR — see option --working-dir.
  • OPAMYES — see options --yes and --confirm-level. OPAMYES has priority over OPAMNO and is ignored if OPAMCONFIRMLEVEL is set.
  • OPAMVAR_var — overrides the contents of the variable var when substituting %{var}% strings in opam files.
  • OPAMVAR_package_var — overrides the contents of the variable package:var when substituting %{package:var}% strings in opam files.

🕰️ CLI VERSION ✨

okay bestie this section is important so listen up 📣 — all scripts and programmatic invocations of opam should use --cli in order to ensure that they work seamlessly with future versions of the opam client. and not just for you! blog posts and other documentation can benefit too, because it prevents information from becoming stale. nobody wants a tutorial that aged like milk 🥛

Although opam only supports roots (~/.opam/) for the current version, it does provide backwards compatibility for its command-line interface. iconic behaviour honestly 👑

Since CLI version support was only added in opam 2.1, use OPAMCLI to select 2.0 support (as opam 2.0 will just ignore it), and --cli=2.1 for 2.1 (or later) versions, since an environment variable controlling the parsing of syntax is brittle. To this end, opam displays a warning if OPAMCLI specifies a valid version other than 2.0, and also if --cli=2.0 is specified. 🚨 yeah, it will call you out, gently.

The command-line version is selected by using the --cli option or the OPAMCLI environment variable. --cli may be specified more than once, where the last instance takes precedence. OPAMCLI is only inspected if --cli is not given. last one wins, always 🌸

💀 EXIT STATUS 💀

okay bestie, this is the part where opam tells you exactly what went wrong by handing back a number, and you're gonna learn every single one of them because they are iconic.

tiny little exception alert!! the exec command is the drama queen that refuses to play by these rules: it returns 127 if the command wasn't found or couldn't be executed at all, and otherwise it just hands you the command's own exit value. periodt.

Here's the whole roster, no skips, no skimming:

  • 0 — Success, or true for boolean queries. we love a win ✨
  • 1 — False. Comes back when a boolean return value is expected, like when you run with --check, or for queries like opam lint. it's not an error bestie it's just no 💅
  • 2 — Bad command-line arguments, or args pointing at an invalid context (think: file not following the expected format). your input said no 🙈
  • 5 — Not found. You asked for something (package, version, repository, etc.) that simply could not be found. she's not here 😭
  • 10 — Aborted. The operation needed confirmation and it never got given. you ghosted the prompt 🫶
  • 15 — Could not acquire the locks required for the operation. locks said no 🔒
  • 20 — There is no solution to the user request. Example: asking to install two incompatible packages. the solver is like "ma'am" 💀
  • 30 — Error in package definition, or other metadata files. Heads up: using --strict raises this error more often. strict mode is strict
  • 31 — Package script error. Some package operations were unsuccessful. This may be an error in the packages or an incompatibility with your system. Also: this can be a partial error.
  • 40 — Sync error. Could not fetch some remotes from the network. Also can be a partial error. the wifi is giving nothing 🦋
  • 50 — Configuration error. Opam or system configuration doesn't allow the operation, and needs fixing. fix it bestie
  • 60 — Solver failure. The solver failed to return a sound answer. Could be a broken external solver, or an error in solver configuration. she's confused 🧚
  • 99 — Internal error. Something went wrong, likely due to a bug in opam itself. not us, it's literally opam
  • 130 — User interrupt. SIGINT was received, generally because the user pressed Ctrl+C. that was you, wasn't it 🙈

and then these three, in their own little crew:

  • 0 on success.
  • 123 on indiscriminate errors reported on standard error.
  • 124 on command line parsing errors.
  • 125 on unexpected internal errors (bugs).

📚 FURTHER DOCUMENTATION 📚

the lore is out there, bestie — go read it:

👑 AUTHORS 👑

these are the actual legends who built this. say thank you. icons, every one of them 🎀

  • David Allsopp <david@tarides.com>
  • Vincent Bernardoff <vb@luminar.eu.org>
  • Raja Boujbel <raja.boujbel@ocamlpro.com>
  • Kate Deplaix <kit-ty-kate@exn.st>
  • Roberto Di Cosmo <roberto@dicosmo.org>
  • Thomas Gazagnaire <thomas@gazagnaire.org>
  • Louis Gesbert <louis.gesbert@ocamlpro.com>
  • Fabrice Le Fessant <Fabrice.Le_fessant@inria.fr>
  • Anil Madhavapeddy <anil@recoil.org>
  • Guillem Rieu <guillem.rieu@ocamlpro.com>
  • Ralf Treinen <ralf.treinen@pps.jussieu.fr>
  • Frederic Tuong <tuong@users.gforge.inria.fr>

🔗 SEE ALSO 🔗

  • opam(1) — the main character herself ✨

🐛 BUGS 🐛

found something cursed? Check bug reports at https://github.com/ocaml/opam/issues. the devs wanna know, fr fr 💜

and that's the whole page bestie!! this was Opam 2.6.1, the OPAM-CLEAN(1) era, and you ate every single section. go forth and opam clean responsibly 💅🌈🫶

📦 where this page comes from