BUNDLE-CONFIG(1)

🎀 bundle-config 🎀

okay so welcome to the bundle-config glow-up, bestie — this is the page from General Commands Manual and it's literally the remote control for all of Bundler's settings ✨. Grab a lil snack, we're going through every single key, no skips. 💅

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🌸 NAME 🌸

bundle-config — Set bundler configuration options. that's it, that's the whole vibe. 🫶

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✨ SYNOPSIS ✨

bundle config [list]
bundle config [get [--local|--global]] NAME
bundle config [set [--local|--global]] NAME VALUE
bundle config unset [--local|--global] NAME

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💖 DESCRIPTION 💖

This command lets you hang out with Bundler's configuration system — like, actually talk to it, read its diary, change its settings. 💅

Bundler loads configuration settings in this exact order, okay? lower on the list = weaker vibe, higher up wins:

1. Local config (<project_root>/.bundle/config or $BUNDLE_APP_CONFIG/config)
2. Environmental variables (ENV)
3. Global config (~/.bundle/config)
4. Bundler default config

🫶 big mood warning: if you execute bundle with the BUNDLE_IGNORE_CONFIG environment variable set, it will straight up ignore all configuration. all of it. every last crumb. 😭

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🦋 SUB-COMMANDS 🦋

list (default command)

Running bundle config list prints out a list of all bundler configuration for the current bundle, plus where that configuration was set. receipts, basically. 🧾✨

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get

Running bundle config get <name> will print the value of that configuration setting, and every location where it was set. iconic detective behaviour ngl 🔍

OPTIONS

• --local — Gets configuration from the configuration file for the local application, namely <project_root>/.bundle/config, or $BUNDLE_APP_CONFIG/config if BUNDLE_APP_CONFIG is set.
• --global — Gets configuration from the configuration file that's global to all bundles executed as the current user, namely from ~/.bundle/config.

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set

Running bundle config set <name> <value> defaults to setting local configuration if you're executing from within a local application — otherwise it sets global configuration. it reads the room bestie 🫶

OPTIONS

• --local — Running bundle config set --local <name> <value> will set that configuration in the directory for the local application. The configuration gets stored in <project_root>/.bundle/config. If BUNDLE_APP_CONFIG is set, the configuration gets stored in $BUNDLE_APP_CONFIG/config instead.
• --global — Running bundle config set --global <name> <value> will set that configuration to the value you specified for all bundles executed as the current user. The configuration gets stored in ~/.bundle/config. Heads up: if name already is set, name will be overridden and the user will be warned. so like, you've been told 💀

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unset

Running bundle config unset <name> will delete the configuration from both the local and global sources. gone. deleted. blocked. 🙈

OPTIONS

• --local — Running bundle config unset --local <name> will delete the configuration only from the local application.
• --global — Running bundle config unset --global <name> will delete the configuration only from the user configuration.

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🌈 CONFIGURATION KEYS 🌈

Configuration keys in bundler have two forms, bestie: the canonical form and the environment variable form. two little outfits for the same setting 💅

For instance, passing the --without flag to bundle install(1) bundle-install.1.html prevents Bundler from installing certain groups specified in the Gemfile(5). Bundler persists this value in app/.bundle/config so that calls to Bundler.setup do not try to find gems from the Gemfile that you didn't install. Additionally, subsequent calls to bundle install(1) bundle-install.1.html remember this setting and skip those groups. memory like an elephant fr fr 🐘

The canonical form of this configuration is "without". To convert the canonical form to the environment variable form, capitalize it and prepend BUNDLE_. The environment variable form of "without" is BUNDLE_WITHOUT. slay ✨

Any periods in the configuration keys must be replaced with two underscores when setting it via environment variables. The configuration key local.rack becomes the environment variable BUNDLE_LOCAL__RACK. that's a double underscore, don't @ me 🫶

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👑 LIST OF AVAILABLE KEYS 👑

The following is a list of all configuration keys and their purpose. You can learn more about their operation in bundle install(1) bundle-install.1.html. buckle up, there's a LOT 💖

• api_request_size (BUNDLE_API_REQUEST_SIZE) — Configure how many dependencies to fetch when resolving the specifications. This configuration is only used when fetching specifications from RubyGems servers that didn't implement the Compact Index API. Defaults to 100.
• auto_install (BUNDLE_AUTO_INSTALL) — Automatically run bundle install when gems are missing.
• bin (BUNDLE_BIN) — If configured, bundle binstubs will install executables from gems in the bundle to the specified directory. Otherwise it will create them in a bin directory relative to the Gemfile directory. These executables run in Bundler's context. If used, you might add this directory to your environment's PATH variable. For instance, if the rails gem comes with a rails executable, bundle binstubs will create a bin/rails executable that ensures that all referred dependencies will be resolved using the bundled gems. cute lil launcher, iconic 🎀
• cache_all (BUNDLE_CACHE_ALL) — Cache all gems, including path and git gems. This needs to be explicitly set before bundler 4, but will be the default on bundler 4.
• cache_all_platforms (BUNDLE_CACHE_ALL_PLATFORMS) — Cache gems for all platforms.
• cache_path (BUNDLE_CACHE_PATH) — The directory that bundler will place cached gems in when running bundle package, and that bundler will look in when installing gems. Defaults to vendor/cache.
• clean (BUNDLE_CLEAN) — Whether Bundler should run bundle clean automatically after bundle install. Defaults to true in Bundler 4, as long as path is not explicitly configured.
• console (BUNDLE_CONSOLE) — The console that bundle console starts. Defaults to irb.
• cooldown (BUNDLE_COOLDOWN) — Number of days a published gem version must age before bundler will resolve to it. Defaults to unset (no cooldown). Pass 0 to disable cooldown for an individual run. 🧊

The effective cooldown for any given gem is resolved from three layers, highest precedence first:

1. CLI flag --cooldown N on install, update, add, and outdated.
2. This setting (bundle config set cooldown N or BUNDLE_COOLDOWN=N).
3. The per-source cooldown: keyword in the Gemfile, such as source "https://rubygems.org", cooldown: 7.

The CLI flag and this setting apply uniformly to every source, including ones declared with their own cooldown: value. To keep a private registry permanently exempt while still cooling down public gems, declare source "https://internal", cooldown: 0 in the Gemfile; remember that --cooldown N on the command line will still override it for that single run. 👑

💀 Important caveat, do not skip this: Cooldown filtering depends on the gem server providing a per-version created_at timestamp in the v2 compact-index format. Versions without that metadata — older gem servers, historical entries that predate the v2 cutover on rubygems.org, or private registries that still emit the v1 format — are treated as outside the cooldown window and remain resolvable. If you rely on cooldown for supply-chain protection, confirm that the gem server emits created_at in its /info/<gem> responses.

• default_cli_command (BUNDLE_DEFAULT_CLI_COMMAND) — The command that running bundle without arguments should run. Defaults to cli_help since Bundler 4, but can also be install, which was the previous default.
• deployment (BUNDLE_DEPLOYMENT) — Equivalent to setting frozen to true and path to vendor/bundle.
• disable_checksum_validation (BUNDLE_DISABLE_CHECKSUM_VALIDATION) — Allow installing gems even if they do not match the checksum provided by RubyGems. 🙈
• disable_exec_load (BUNDLE_DISABLE_EXEC_LOAD) — Stop Bundler from using load to launch an executable in-process in bundle exec.
• disable_local_branch_check (BUNDLE_DISABLE_LOCAL_BRANCH_CHECK) — Allow Bundler to use a local git override without a branch specified in the Gemfile.
• disable_local_revision_check (BUNDLE_DISABLE_LOCAL_REVISION_CHECK) — Allow Bundler to use a local git override without checking if the revision present in the lockfile is present in the repository.
• disable_shared_gems (BUNDLE_DISABLE_SHARED_GEMS) — Stop Bundler from accessing gems installed to RubyGems' normal location.
• disable_version_check (BUNDLE_DISABLE_VERSION_CHECK) — Stop Bundler from checking if a newer Bundler version is available on rubygems.org.
• force_ruby_platform (BUNDLE_FORCE_RUBY_PLATFORM) — Ignore the current machine's platform and install only ruby platform gems. As a result, gems with native extensions will be compiled from source. good luck bestie 🧚
• frozen (BUNDLE_FROZEN) — Disallow any automatic changes to Gemfile.lock. Bundler commands will be blocked unless the lockfile can be installed exactly as written. Usually this will happen when changing the Gemfile manually and forgetting to update the lockfile through bundle lock or bundle install. no touching. locked. literally. 🔒
• gem.github_username (BUNDLE_GEM__GITHUB_USERNAME) — Sets a GitHub username or organization to be used in the README and .gemspec files when you create a new gem via bundle gem command. It can be overridden by passing an explicit --github-username flag to bundle gem.
• gem.push_key (BUNDLE_GEM__PUSH_KEY) — Sets the --key parameter for gem push when using the rake release command with a private gemstash server.
• gemfile (BUNDLE_GEMFILE) — The name of the file that bundler should use as the Gemfile. This location of this file also sets the root of the project, which is used to resolve relative paths in the Gemfile, among other things. By default, bundler will search up from the current working directory until it finds a Gemfile. it's giving main character energy, the file that defines the whole project ✨
• global_gem_cache (BUNDLE_GLOBAL_GEM_CACHE) — Whether Bundler should cache all gems and compiled extensions globally, rather than locally to the configured installation path.
• ignore_funding_requests (BUNDLE_IGNORE_FUNDING_REQUESTS) — When set, no funding requests will be printed. respectfully, not today 💅
• ignore_messages (BUNDLE_IGNORE_MESSAGES) — When set, no post install messages will be printed. To silence a single gem, use dot notation like ignore_messages.httparty true.
• init_gems_rb (BUNDLE_INIT_GEMS_RB) — Generate a gems.rb instead of a Gemfile when running bundle init.
• jobs (BUNDLE_JOBS) — The number of gems Bundler can download and install in parallel. Defaults to the number of available processors. multithreading, we love to see it 🔥
• lockfile (BUNDLE_LOCKFILE) — The path to the lockfile that bundler should use. By default, Bundler adds .lock to the end of the gemfile entry. Can be set to false in the Gemfile to disable lockfile creation entirely (see gemfile(5)).
• lockfile_checksums (BUNDLE_LOCKFILE_CHECKSUMS) — Whether Bundler should include a checksums section in new lockfiles, to protect from compromised gem sources. Defaults to true. safety first babes 🛡️

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and that's where part one wraps, but we are NOT done — more of this page is coming, so stay perched 🦋

• no_install (BUNDLE_NO_INSTALL) — lowkey the "don't actually install anything" switch 💅 it controls whether bundle package should skip installing gems.
• no_prune (BUNDLE_NO_PRUNE) — tells Bundler to leave outdated gems unpruned when caching, so nothing gets yeeted that you didn't ask to be yeeted.
• only (BUNDLE_ONLY) — a space-separated list of groups, and Bundler installs only the gems in those groups. 🎀 but bestie, read this twice: please check carefully if you want to install also gems without a group, because they get put inside the default group. For example only test:default will install all gems specified in the test group and the ones without one.
• path (BUNDLE_PATH) — the location on disk where all gems in your bundle will be located, regardless of $GEM_HOME or $GEM_PATH values. Bundle gems not found in this location will be installed by bundle install. ✨ when not set, Bundler installs by default to a .bundle directory relative to repository root in Bundler 4, and to the default system path (Gem.dir) before Bundler 4. That means that before Bundler 4, Bundler shares this location with Rubygems, and gem install ... will have gems installed in the same location — and therefore, gems installed without path set will show up by calling gem list. 👀 This will not be the case in Bundler 4.
• path.system (BUNDLE_PATH__SYSTEM) — whether Bundler will install gems into the default system path (Gem.dir).
• plugins (BUNDLE_PLUGINS) — enable Bundler's experimental plugin system 🧚 (experimental!! you've been warned, it's giving "handle with care").
• prefer_patch (BUNDLE_PREFER_PATCH) — prefer updating only to the next patch version during updates. Makes bundle update calls equivalent to bundler update --patch. 🔥
• redirect (BUNDLE_REDIRECT) — the number of redirects allowed for network requests. Defaults to 5.
• retry (BUNDLE_RETRY) — the number of times to retry failed network requests. Defaults to 3.
• shebang (BUNDLE_SHEBANG) — the program name that should be invoked for generated binstubs. Defaults to the ruby install name used to generate the binstub.
• silence_deprecations (BUNDLE_SILENCE_DEPRECATIONS) — whether Bundler should silence deprecation warnings for behavior that will be changed in the next major version. 🙈 (it's giving "I'm ignoring my problems" but make it config.)
• silence_root_warning (BUNDLE_SILENCE_ROOT_WARNING) — silence the warning Bundler prints when installing gems as root.
• simulate_version (BUNDLE_SIMULATE_VERSION) — the virtual version Bundler should use for activating feature flags. Can be used to simulate all the new functionality that will be enabled in a future major version 🔮 very main character, very time-travel.
• ssl_ca_cert (BUNDLE_SSL_CA_CERT) — path to a designated CA certificate file or folder containing multiple certificates for trusted CAs in PEM format.
• ssl_client_cert (BUNDLE_SSL_CLIENT_CERT) — path to a designated file containing a X.509 client certificate and key in PEM format.
• ssl_verify_mode (BUNDLE_SSL_VERIFY_MODE) — the SSL verification mode Bundler uses when making HTTPS requests. Defaults to verify peer.
• system_bindir (BUNDLE_SYSTEM_BINDIR) — the location where RubyGems installs binstubs. Defaults to Gem.bindir.
• timeout (BUNDLE_TIMEOUT) — the seconds allowed before timing out for network requests. Defaults to 10.
• update_requires_all_flag (BUNDLE_UPDATE_REQUIRES_ALL_FLAG) — require passing --all to bundle update when everything should be updated, and disallow passing no options to bundle update. 🫶 boundaries!! we love them.
• user_agent (BUNDLE_USER_AGENT) — the custom user agent fragment Bundler includes in API requests.
• verbose (BUNDLE_VERBOSE) — whether Bundler should print verbose output. Defaults to false, unless the --verbose CLI flag is used.
• version (BUNDLE_VERSION) — the version of Bundler to use when running under Bundler environment. Defaults to lockfile. You can also specify system or x.y.z. lockfile will use the Bundler version specified in the Gemfile.lock, system will use the system version of Bundler, and x.y.z will use the specified version of Bundler. 💅 pick your fighter.
• with (BUNDLE_WITH) — a space-separated or :-separated list of groups whose gems bundler should install.
• without (BUNDLE_WITHOUT) — a space-separated or :-separated list of groups whose gems bundler should not install.

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🔨 BUILD OPTIONS 🔨

You can use bundle config to give Bundler the flags to pass to the gem installer every time bundler tries to install a particular gem. ✨ like setting defaults but for gem builds, iykyk.

A very common example, the mysql gem, requires Snow Leopard users to pass configuration flags to gem install to specify where to find the mysql_config executable.

gem install mysql -- --with-mysql-config=/usr/local/mysql/bin/mysql_config

Since the specific location of that executable can change from machine to machine, you can specify these flags on a per-machine basis. 🖥️✨

bundle config set --global build.mysql --with-mysql-config=/usr/local/mysql/bin/mysql_config

After running this command, every time bundler needs to install the mysql gem, it will pass along the flags you specified. no cap, it just remembers for you 💖

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🧚 LOCAL GIT REPOS 🧚

Bundler also allows you to work against a git repository locally instead of using the remote version. This can be achieved by setting up a local override:

bundle config set --local local.GEM_NAME /path/to/local/git/repository

Important: 🚨 This feature only works for gems that are specified with a git source in your Gemfile. It does not work for gems installed from RubyGems or other sources. The gem must be defined with git: option pointing to a remote repository.

For example, if your Gemfile contains:

gem "rack", git: "https://github.com/rack/rack.git", branch: "main"

Then you can use a local Rack repository by running:

bundle config set --local local.rack ~/Work/git/rack

Now instead of checking out the remote git repository, the local override will be used. Similar to a path source, every time the local git repository change, changes will be automatically picked up by Bundler. This means a commit in the local git repo will update the revision in the Gemfile.lock to the local git repo revision. ⚠️ This requires the same attention as git submodules. Before pushing to the remote, you need to ensure the local override was pushed, otherwise you may point to a commit that only exists in your local machine. You'll also need to CGI escape your usernames and passwords as well.

Bundler does many checks to ensure a developer won't work with invalid references. Particularly, we force a developer to specify a branch in the Gemfile in order to use this feature. If the branch specified in the Gemfile and the current branch in the local git repository do not match, Bundler will abort. 🛑 This ensures that a developer is always working against the correct branches, and prevents accidental locking to a different branch. (iconic safety behaviour tbh)

Finally, Bundler also ensures that the current revision in the Gemfile.lock exists in the local git repository. By doing this, Bundler forces you to fetch the latest changes in the remotes. 🔥

If you need to temporarily use a local version of a gem that is normally installed from RubyGems (not from git), use a path source instead:

gem "rack", path: "~/Work/git/rack"

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🪞 MIRRORS OF GEM SOURCES 🪞

Bundler supports overriding gem sources with mirrors. This allows you to configure rubygems.org as the gem source in your Gemfile while still using your mirror to fetch gems. 💅 sneaky but sanctioned.

bundle config set --global mirror.SOURCE_URL MIRROR_URL

For example, to use a mirror of https://rubygems.org hosted at https://example.org:

bundle config set --global mirror.https://rubygems.org https://example.org

Each mirror also provides a fallback timeout setting. If the mirror does not respond within the fallback timeout, Bundler will try to use the original server instead of the mirror. 🎀 bestie backup plan.

bundle config set --global mirror.SOURCE_URL.fallback_timeout TIMEOUT

For example, to fall back to rubygems.org after 3 seconds:

bundle config set --global mirror.https://rubygems.org.fallback_timeout 3

The default fallback timeout is 0.1 seconds, but the setting can currently only accept whole seconds (for example, 1, 15, or 30). 🌸

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🔐 CREDENTIALS FOR GEM SOURCES 🔐

Bundler allows you to configure credentials for any gem source, which allows you to avoid putting secrets into your Gemfile. 💀 please, do NOT put secrets in your Gemfile, we beg.

bundle config set --global SOURCE_HOSTNAME USERNAME:PASSWORD

For example, to save the credentials of user claudette for the gem source at gems.longerous.com, you would run:

bundle config set --global gems.longerous.com claudette:s00pers3krit

Or you can set the credentials as an environment variable like this:

export BUNDLE_GEMS__LONGEROUS__COM="claudette:s00pers3krit"

For gems with a git source with HTTP(S) URL you can specify credentials like so:

bundle config set --global https://github.com/ruby/rubygems.git username:password

Or you can set the credentials as an environment variable like so:

export BUNDLE_GITHUB__COM=username:password

This is especially useful for private repositories on hosts such as GitHub, where you can use personal OAuth tokens: 🔥

export BUNDLE_GITHUB__COM=abcd0123generatedtoken:x-oauth-basic

Note that any configured credentials will be redacted by informative commands such as bundle config list or bundle config get, unless you use the --parseable flag. This is to avoid unintentionally leaking credentials when copy-pasting bundler output. 🙈💖 (very "protect the bestie" of them.)

Also note that to guarantee a sane mapping between valid environment variable names and valid host names, bundler makes the following transformations:

• Any - characters in a host name are mapped to a triple underscore (___) in the corresponding environment variable.
• Any . characters in a host name are mapped to a double underscore (__) in the corresponding environment variable.

This means that if you have a gem server named my.gem-host.com, you'll need to use the BUNDLE_MY__GEM___HOST__COM variable to configure credentials for it through ENV. ⭐

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🗂️ CONFIGURE BUNDLER DIRECTORIES 🗂️

Bundler's home, cache and plugin directories and config file can be configured through environment variables. The default location for Bundler's home directory is ~/.bundle, which all directories inherit from by default. The following outlines the available environment variables and their default values ✨

BUNDLE_USER_HOME : $HOME/.bundle
BUNDLE_USER_CACHE : $BUNDLE_USER_HOME/cache
BUNDLE_USER_CONFIG : $BUNDLE_USER_HOME/config
BUNDLE_USER_PLUGIN : $BUNDLE_USER_HOME/plugin

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and that's the whole page bestie, you ate that 💅✨ go configure something gorgeous 🎀🦋

BUNDLE-CONFIG(1) — Bundler docs, dated April 2026, bow down to the version stamp 👑🌸