MODULE.bazel files

Methods available in MODULE.bazel files.

Members

• archive_override
• bazel_dep
• flag_alias
• git_override
• include
• inject_repo
• local_path_override
• module
• multiple_version_override
• override_repo
• register_execution_platforms
• register_toolchains
• single_version_override
• use_extension
• use_repo
• use_repo_rule

archive_override

None archive_override(*, module_name, **kwargs)

Specifies that this dependency should come from an archive file (zip, gzip, etc) at a certain location, instead of from a registry. Effectively, this dependency will be backed by an http_archive rule.

This directive only takes effect in the root module; in other words, if a module is used as a dependency by others, its own overrides are ignored.

Parameters

Parameter	Description
module_name	string; required The name of the Bazel module dependency to apply this override to.
kwargs	required All other arguments are forwarded to the underlying http_archive repo rule. Note that the name attribute shouldn’t be specified; use module_name instead.

bazel_dep

None bazel_dep(*, name, version='', max_compatibility_level=-1, repo_name='', dev_dependency=False)

Declares a direct dependency on another Bazel module.

Parameters

Parameter	Description
name	string; required The name of the module to be added as a direct dependency.
version	string; default is '' The version of the module to be added as a direct dependency.
max_compatibility_level	int; default is -1 Deprecated. This is now a no-op and has no effect.
repo_name	string; or None; default is '' The name of the external repo representing this dependency. This is by default the name of the module. Can be set to None to make this dependency a “nodep” dependency: in this case, this bazel_dep specification is only honored if the target module already exists in the dependency graph by some other means.
dev_dependency	bool; default is False If true, this dependency will be ignored if the current module is not the root module or --ignore_dev_dependency is enabled.

flag_alias

None flag_alias(*, name, starlark_flag)

Maps a command-line flag —foo to a Starlark flag —@repo//defs:foo. Bazel translates all instances of $bazel build //target --foo to$ bazel build //target —@repo//defs:foo.

Parameters

Parameter	Description
name	string; required The name of the flag.
starlark_flag	string; required The label of the Starlark flag to alias to.

git_override

None git_override(*, module_name, **kwargs)

Specifies that this dependency should come from a certain commit in a Git repository, instead of from a registry. Effectively, this dependency will be backed by a git_repository rule.

This directive only takes effect in the root module; in other words, if a module is used as a dependency by others, its own overrides are ignored.

Parameters

Parameter	Description
module_name	string; required The name of the Bazel module dependency to apply this override to.
kwargs	required All other arguments are forwarded to the underlying git_repository repo rule. Note that the name attribute shouldn’t be specified; use module_name instead.

include

None include(label)

Includes the contents of another MODULE.bazel-like file. Effectively, include() behaves as if the included file is textually placed at the location of the include() call, except that variable bindings (such as those used for use_extension) are only ever visible in the file they occur in, not in any included or including files.

Only the root module and modules subject to a non-registry override may use include().

Only files in the current module’s repo may be included.

include() allows you to segment a module file into multiple parts, to avoid having an enormous MODULE.bazel file or to better manage access control for individual semantic segments.

Parameters

Parameter	Description
label	string; required The label pointing to the file to include. The label must point to a file in the main repo; in other words, it must start with double slashes (//). The name of the file must end with .MODULE.bazel and must not start with ..

inject_repo

None inject_repo(extension_proxy, *args, **kwargs)

Injects one or more new repos into the given module extension. This is ignored if the current module is not the root module or --ignore_dev_dependency is enabled.

Use override_repo instead to override an existing repo.

Parameters

Parameter	Description
extension_proxy	module_extension_proxy; required A module extension proxy object returned by a use_extension call.
args	required The repos visible to the current module that should be injected into the extension under the same name.
kwargs	required The new repos to inject into the extension, where the values are the names of repos in the scope of the current module and the keys are the name they will be visible under in the extension. Keys that are not valid identifiers can be specified via a literal dict passed as extra keyword arguments, e.g., inject_repo(extension_proxy, **{"foo.2": "foo"}).

local_path_override

None local_path_override(*, module_name, path)

Specifies that this dependency should come from a certain directory on local disk, instead of from a registry. Effectively, this dependency will be backed by a local_repository rule.

This directive only takes effect in the root module; in other words, if a module is used as a dependency by others, its own overrides are ignored.

Parameters

Parameter	Description
module_name	string; required The name of the Bazel module dependency to apply this override to.
path	string; required The path to the directory where this module is.

module

None module(*, name='', version='', compatibility_level=-1, repo_name='', bazel_compatibility=[])

Declares certain properties of the Bazel module represented by the current Bazel repo. These properties are either essential metadata of the module (such as the name and version), or affect behavior of the current module and its dependents.

It should be called at most once, and if called, it must be the very first directive in the MODULE.bazel file. It can be omitted only if this module is the root module (as in, if it’s not going to be depended on by another module).

Parameters

Parameter	Description
name	string; default is '' The name of the module. Can be omitted only if this module is the root module (as in, if it’s not going to be depended on by another module). A valid module name must: 1) only contain lowercase letters (a-z), digits (0-9), dots (.), hyphens (-), and underscores (_); 2) begin with a lowercase letter; 3) end with a lowercase letter or digit.
version	string; default is '' The version of the module. Can be omitted only if this module is the root module (as in, if it’s not going to be depended on by another module). The version must be in a relaxed SemVer format; see the documentation for more details.
compatibility_level	int; default is -1 Deprecated. This is now a no-op and has no effect.
repo_name	string; default is '' The name of the repository representing this module, as seen by the module itself. By default, the name of the repo is the name of the module. This can be specified to ease migration for projects that have been using a repo name for itself that differs from its module name.
bazel_compatibility	Iterable of strings; default is [] A list of bazel versions that allows users to declare which Bazel versions are compatible with this module. It does NOT affect dependency resolution, but bzlmod will use this information to check if your current Bazel version is compatible. The format of this value is a string of some constraint values separated by comma. Three constraints are supported: <=X.X.X: The Bazel version must be equal or older than X.X.X. Used when there is a known incompatible change in a newer version. >=X.X.X: The Bazel version must be equal or newer than X.X.X.Used when you depend on some features that are only available since X.X.X. -X.X.X: The Bazel version X.X.X is not compatible. Used when there is a bug in X.X.X that breaks you, but fixed in later versions.

multiple_version_override

None multiple_version_override(*, module_name, versions, registry='')

Specifies that a dependency should still come from a registry, but multiple versions of it should be allowed to coexist. See the documentation for more details. This directive only takes effect in the root module; in other words, if a module is used as a dependency by others, its own overrides are ignored.

Parameters

Parameter	Description
module_name	string; required The name of the Bazel module dependency to apply this override to.
versions	Iterable of strings; required Explicitly specifies the versions allowed to coexist. These versions must already be present in the dependency graph pre-selection. Dependencies on this module will be “upgraded” to the nearest higher allowed version at the same compatibility level, whereas dependencies that have a higher version than any allowed versions at the same compatibility level will cause an error.
registry	string; default is '' Overrides the registry for this module; instead of finding this module from the default list of registries, the given registry should be used.

override_repo

None override_repo(extension_proxy, *args, **kwargs)

Overrides one or more repos defined by the given module extension with the given repos visible to the current module. This is ignored if the current module is not the root module or --ignore_dev_dependency is enabled.

Use inject_repo instead to add a new repo.

Parameters

Parameter	Description
extension_proxy	module_extension_proxy; required A module extension proxy object returned by a use_extension call.
args	required The repos in the extension that should be overridden with the repos of the same name in the current module.
kwargs	required The overrides to apply to the repos generated by the extension, where the values are the names of repos in the scope of the current module and the keys are the names of the repos they will override in the extension. Keys that are not valid identifiers can be specified via a literal dict passed as extra keyword arguments, e.g., override_repo(extension_proxy, **{"foo.2": "foo"}).

register_execution_platforms

None register_execution_platforms(*platform_labels, dev_dependency=False)

Specifies already-defined execution platforms to be registered when this module is selected. Should be absolute target patterns (ie. beginning with either @ or //). See toolchain resolution for more information. Patterns that expand to multiple targets, such as :all, will be registered in lexicographical order by name.

Parameters

Parameter	Description
dev_dependency	bool; default is False If true, the execution platforms will not be registered if the current module is not the root module or --ignore_dev_dependency is enabled.
platform_labels	sequence of strings; required The target patterns to register.

register_toolchains

None register_toolchains(*toolchain_labels, dev_dependency=False)

Specifies already-defined toolchains to be registered when this module is selected. Should be absolute target patterns (ie. beginning with either @ or //). See toolchain resolution for more information. Patterns that expand to multiple targets, such as :all, will be registered in lexicographical order by target name (not the name of the toolchain implementation).

Parameters

Parameter	Description
dev_dependency	bool; default is False If true, the toolchains will not be registered if the current module is not the root module or --ignore_dev_dependency is enabled.
toolchain_labels	sequence of strings; required The target patterns to register.

single_version_override

None single_version_override(*, module_name, version='', registry='', patches=[], patch_cmds=[], patch_strip=0)

Specifies that a dependency should still come from a registry, but its version should be pinned, or its registry overridden, or a list of patches applied. This directive only takes effect in the root module; in other words, if a module is used as a dependency by others, its own overrides are ignored.

Parameters

Parameter	Description
module_name	string; required The name of the Bazel module dependency to apply this override to.
version	string; default is '' Overrides the declared version of this module in the dependency graph. In other words, this module will be “pinned” to this override version. This attribute can be omitted if all one wants to override is the registry or the patches.
registry	string; default is '' Overrides the registry for this module; instead of finding this module from the default list of registries, the given registry should be used.
patches	Iterable of strings; default is [] A list of labels pointing to patch files to apply for this module. The patch files must exist in the source tree of the top level project. They are applied in the list order. If a patch makes changes to the MODULE.bazel file, these changes will only be effective if the patch file is provided by the root module.
patch_cmds	Iterable of strings; default is [] Sequence of Bash commands to be applied on Linux/Macos after patches are applied. Changes to the MODULE.bazel file will not be effective.
patch_strip	int; default is 0 Same as the —strip argument of Unix patch.

use_extension

module_extension_proxy use_extension(extension_bzl_file, extension_name, *, dev_dependency=False, isolate=False)

Returns a proxy object representing a module extension; its methods can be invoked to create module extension tags.

Parameters

Parameter	Description
extension_bzl_file	string; required A label to the Starlark file defining the module extension.
extension_name	string; required The name of the module extension to use. A symbol with this name must be exported by the Starlark file.
dev_dependency	bool; default is False If true, this usage of the module extension will be ignored if the current module is not the root module or --ignore_dev_dependency is enabled.
isolate	bool; default is False Experimental. This parameter is experimental and may change at any time. Please do not depend on it. It may be enabled on an experimental basis by setting --experimental_isolated_extension_usages If true, this usage of the module extension will be isolated from all other usages, both in this and other modules. Tags created for this usage do not affect other usages and the repositories generated by the extension for this usage will be distinct from all other repositories generated by the extension. This parameter is currently experimental and only available with the flag --experimental_isolated_extension_usages.

use_repo

None use_repo(extension_proxy, *args, **kwargs)

Imports one or more repos generated by the given module extension into the scope of the current module.

Parameters

Parameter	Description
extension_proxy	module_extension_proxy; required
args	required The names of the repos to import.
kwargs	required Specifies certain repos to import into the scope of the current module with different names. The keys should be the name to use in the current scope, whereas the values should be the original names exported by the module extension. Keys that are not valid identifiers can be specified via a literal dict passed as extra keyword arguments, e.g., use_repo(extension_proxy, **{"foo.2": "foo"}).

use_repo_rule

repo_rule_proxy use_repo_rule(repo_rule_bzl_file, repo_rule_name)

Returns a proxy value that can be directly invoked in the MODULE.bazel file as a repository rule, one or more times. Repos created in such a way are only visible to the current module, under the name declared using the name attribute on the proxy. The implicit Boolean dev_dependency attribute can also be used on the proxy to denote that a certain repo is only to be created when the current module is the root module.

Parameters

Parameter	Description
repo_rule_bzl_file	string; required A label to the Starlark file defining the repo rule.
repo_rule_name	string; required The name of the repo rule to use. A symbol with this name must be exported by the Starlark file.