BUNDLE-CONFIG(1)

📦
version 4.0.18 · 10 versions
, in ubuntu stonking

bundle-config(1) — from the General Commands Manual, bestie 💖 this is literally the settings app for Bundler, and we’re going through it together. No skipped details, fr fr.

✨ NAME ✨

bundle-config — Set bundler configuration options. Short, iconic, does exactly what it says on the tin 💅.

✨ SYNOPSIS ✨

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

✨ DESCRIPTION ✨

okay so this command lets you interact with Bundler’s configuration system. Bundler loads configuration settings in this order:

  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

Executing bundle with the BUNDLE_IGNORE_CONFIG environment variable set will cause it to ignore all configuration. Bye settings, you’re not seeing them 👋😭.

🛠️ SUB-COMMANDS 🛠️

📋 list (default command)

Executing bundle config list will print a list of all bundler configuration for the current bundle, and where that configuration was set. It’s giving receipts for every setting 💅.

🔍 get

Executing bundle config get <name> will print the value of that configuration setting, and all locations where it was set. Yes bestie, all the lore 🕵️♀️.

OPTIONS

  • --local — Get 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 — Get configuration from the configuration file global to all bundles executed as the current user, namely from ~/.bundle/config.

🛠️ set

Executing bundle config set <name> <value> defaults to setting local configuration if executing from within a local application, otherwise it will set global configuration. It picks a lane automatically, main character energy ✨.

OPTIONS

  • --local — Executing bundle config set --local <name> <value> will set that configuration in the directory for the local application. The configuration will be stored in <project_root>/.bundle/config. If BUNDLE_APP_CONFIG is set, the configuration will be stored in $BUNDLE_APP_CONFIG/config.
  • --global — Executing bundle config set --global <name> <value> will set that configuration to the value specified for all bundles executed as the current user. The configuration will be stored in ~/.bundle/config. If name already is set, name will be overridden and user will be warned. Warning received, bestie 💀.

🗑️ unset

Executing bundle config unset <name> will delete the configuration in both local and global sources. Both. Gone. 💅

OPTIONS

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

🔑 CONFIGURATION KEYS 🔑

Configuration keys in bundler have two forms: the canonical form and the environment variable form. Two forms, one vibe ✌️.

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.

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.

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. Two underscores, not one — periodt 🎀.

📚 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.

  • 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. It just does it, no asking.
  • 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. Very handy, lowkey 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.

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. That’s the fine print, bestie — read it 🫶.

  • 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. Big “compiling in the club” energy 🔥.
  • 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. Frozen is serious, bestie 🧊.
  • 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 the 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. The 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.
  • 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.
  • 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.
  • 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 slide a checksums section into brand-new lockfiles so a compromised gem source can't do sneaky lil crimes 💅. Defaults to true. Oh and heads up: Bundler's own checksum only gets included when its .gem file is cached, which lowkey might not be the situation when Bundler is installed as a default gem.
  • no_install (BUNDLE_NO_INSTALL) — whether bundle package should skip installing gems entirely. Just... not installing. Skipping. ✨
  • no_prune (BUNDLE_NO_PRUNE) — whether Bundler should leave outdated gems unpruned when caching.
  • only (BUNDLE_ONLY) — a space-separated list of groups, and only gems in those groups get installed. 🎀 Please check carefully if you also wanna install the group-less gems, because those get tucked inside the default group. Like, for example only test:default will install all gems specified in the test group and the ones without a group at all.
  • path (BUNDLE_PATH) — the spot on disk where all the gems in your bundle live, no matter what $GEM_HOME or $GEM_PATH say. Any bundle gems not found there get installed by bundle install. When it's not set, Bundler installs by default to a .bundle directory relative to the repository root in Bundler 4, and to the default system path (Gem.dir) before Bundler 4. Which means: before Bundler 4, Bundler shares that location with RubyGems, so gem install ... puts gems in the same place, and therefore gems installed without path set will show up when you call gem list. 👀 That 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) — turn on Bundler's experimental plugin system. (experimental!! we don't gatekeep, but we do warn 🧚)
  • prefer_patch (BUNDLE_PREFER_PATCH) — prefer updating only to the next patch version during updates. Makes bundle update calls equivalent to bundler update --patch. slay.
  • redirect (BUNDLE_REDIRECT) — how many redirects are allowed for network requests. Defaults to 5.
  • retry (BUNDLE_RETRY) — how many 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 hush the deprecation warnings for behavior that's getting changed in the next major version. 🙈
  • silence_root_warning (BUNDLE_SILENCE_ROOT_WARNING) — silence the warning Bundler prints when you install gems as root.
  • simulate_version (BUNDLE_SIMULATE_VERSION) — the virtual version Bundler should use for activating feature flags. You can use it to simulate all the shiny new functionality that'll be enabled in a future major version. main character energy for real.
  • ssl_ca_cert (BUNDLE_SSL_CA_CERT) — path to a designated CA certificate file, or a folder containing multiple certificates for trusted CAs, in PEM format.
  • ssl_client_cert (BUNDLE_SSL_CLIENT_CERT) — path to a designated file containing an 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) — where RubyGems installs binstubs. Defaults to Gem.bindir.
  • timeout (BUNDLE_TIMEOUT) — the seconds allowed before a network request times out. 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. no vibes-based updating here 💀
  • 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 a Bundler environment. Defaults to lockfile. You can also specify system or x.y.z. lockfile uses the Bundler version specified in the Gemfile.lock, system uses the system version of Bundler, and x.y.z uses the specified version of Bundler. 🦋
  • 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.

🛠️ BUILD OPTIONS 🛠️

Okay so bestie, you can use bundle config to hand Bundler the flags it should pass to the gem installer every single time bundler tries to install a particular gem. like a little note pinned to the fridge 🫶

A super 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

And since the exact 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 you run this command, every time bundler needs to install the mysql gem, it will pass along the flags you specified. iconic behavior honestly ✨

🌿 LOCAL GIT REPOS 🌿

Bundler also lets you work against a git repository locally instead of using the remote version. You do it 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 the git: option pointing to a remote repository. no cap.

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 gets used. Similar to a path source, every time the local git repository changes, the changes are automatically picked up by Bundler. Which means a commit in the local git repo will update the revision in the Gemfile.lock to the local git repo revision. 💅

But this requires the same attention as git submodules, bestie. Before pushing to the remote, you need to make sure the local override was pushed, otherwise you may point to a commit that only exists on 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 makes sure a developer is always working against the correct branches, and prevents accidental locking to a different branch. very protective, we love a boundary-setting tool 🎀

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's normally installed from RubyGems (not from git), use a path source instead:

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

🪞 MIRRORS OF GEM SOURCES 🪞

Bundler supports overriding gem sources with mirrors 🦋. This lets you configure rubygems.org as the gem source in your Gemfile while still using your mirror to fetch gems.

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 doesn't respond within the fallback timeout, Bundler will try to use the original server instead of the mirror. (a little backup plan, we love to see it 💖)

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). so like... don't get cute with decimals 🙈

🔐 CREDENTIALS FOR GEM SOURCES 🔐

Bundler lets you configure credentials for any gem source, which means you can avoid putting secrets into your Gemfile. periodt. 🔥

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. please do not accidentally dox yourself bestie 😭

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. 🧚 iykyk

🎀 CONFIGURE BUNDLER DIRECTORIES 🎀

okay so real talk, bestie: Bundler's home, cache and plugin directories plus its config file can all be configured through environment variables. The default location for Bundler's home directory is ~/.bundle, and all the directories inherit from it by default. the way that works is honestly iconic 💅

here are the available environment variables and their default values, no cap 👑

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
vibe check ✅ — those defaults are literally the blueprint, and every one of those paths is inheriting the home-directory energy by default 🫶

💖 that's the whole BUNDLE-CONFIG(1) moment, bestie — April 2026 edition, signing off with main character energy 🫶✨

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