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Build configuration


All build configuration is defined in the tool.hatch.build table.

Build targets are defined as sections within tool.hatch.build.targets:

[tool.hatch.build.targets.<TARGET_NAME>]
[build.targets.<TARGET_NAME>]

For each build target you may override any of the defaults set in the top-level tool.hatch.build table.

Build system

To be compatible with the broader Python packaging ecosystem, you must define the build system as follows:

[build-system]
requires = ["hatchling"]
build-backend = "hatchling.build"

The version of hatchling defined here will be used to build all targets.

Hatchling is a PEP 517/PEP 660 compatible build backend and is a dependency of Hatch itself.

File selection

VCS

By default, Hatch will respect the first .gitignore or .hgignore file found in your project's root directory or parent directories. Set ignore-vcs to true to disable this behavior:

[tool.hatch.build]
ignore-vcs = true
[build]
ignore-vcs = true

Note

For .hgignore files only glob syntax is supported.

Patterns

You can set the include and exclude options to select exactly which files will be shipped in each build, with exclude taking precedence. Every entry represents a Git-style glob pattern.

For example, the following configuration:

[tool.hatch.build]
include = [
  "pkg/*.py",
  "/tests",
]
exclude = [
  "*.json",
  "pkg/_compat.py",
]
[build]
include = [
  "pkg/*.py",
  "/tests",
]
exclude = [
  "*.json",
  "pkg/_compat.py",
]

will exclude every file with a .json extension, and will include everything under a tests directory located at the root and every file with a .py extension that is directly under a pkg directory located at the root except for _compat.py.

Artifacts

If you want to include files that are ignored by your VCS, such as those that might be created by build hooks, you can use the artifacts option. This option is semantically equivalent to include.

Note that artifacts are not affected by the exclude option. Artifacts can be excluded by using more explicit paths or by using the ! negation operator. When using the ! operator, the negated pattern(s) must come after the more generic ones.

[tool.hatch.build]
artifacts = [
  "*.so",
  "*.dll",
  "!/foo/*.so",
]
[build]
artifacts = [
  "*.so",
  "*.dll",
  "!/foo/*.so",
]

Explicit selection

Generic

You can use the only-include option to prevent directory traversal starting at the project root and only select specific relative paths to directories or files. Using this option ignores any defined include patterns.

[tool.hatch.build.targets.wheel]
only-include = ["pkg", "tests/unit"]
[build.targets.wheel]
only-include = ["pkg", "tests/unit"]

Packages

The packages option is semantically equivalent to only-include (which takes precedence) except that the shipped path will be collapsed to only include the final component.

So for example, if you want to ship a package foo that is stored in a directory src you would do:

[tool.hatch.build.targets.wheel]
packages = ["src/foo"]
[build.targets.wheel]
packages = ["src/foo"]

Forced inclusion

The force-include option allows you to select specific files or directories from anywhere on the file system that should be included and map them to the desired relative distribution path.

For example, if there was a directory alongside the project root named artifacts containing a file named lib.so and a file named lib.h in your home directory, you could ship both files in a pkg directory with the following configuration:

[tool.hatch.build.targets.wheel.force-include]
"../artifacts" = "pkg"
"~/lib.h" = "pkg/lib.h"
[build.targets.wheel.force-include]
"../artifacts" = "pkg"
"~/lib.h" = "pkg/lib.h"

Note

  • Files must be mapped exactly to their desired paths, not to directories.
  • The contents of directory sources are recursively included.
  • To map directory contents directly to the root use / (a forward slash).
  • Sources that do not exist are silently ignored.

Warning

Files included using this option will overwrite any file path that was already included by other file selection options.

Default file selection

If no file selection options are provided, then what gets included is determined by each build target.

Excluding files outside packages

If you want to exclude non-artifact files that do not reside within a Python package, set only-packages to true:

[tool.hatch.build]
only-packages = true
[build]
only-packages = true

Rewriting paths

You can rewrite relative paths to directories with the sources option. For example, the following configuration:

[tool.hatch.build.sources]
"src/foo" = "bar"
[build.sources]
"src/foo" = "bar"

would distribute the file src/foo/file.ext as bar/file.ext.

If you want to remove path prefixes entirely, rather than setting each to an empty string, you can define sources as an array:

[tool.hatch.build]
sources = ["src"]
[build]
sources = ["src"]

The packages option itself relies on sources. Defining packages = ["src/foo"] for the wheel target is equivalent to the following:

[tool.hatch.build.targets.wheel]
only-include = ["src/foo"]
sources = ["src"]
[build.targets.wheel]
only-include = ["src/foo"]
sources = ["src"]

Performance

All encountered directories are traversed by default. To skip non-artifact directories that are excluded, set skip-excluded-dirs to true:

[tool.hatch.build]
skip-excluded-dirs = true
[build]
skip-excluded-dirs = true

Warning

This may result in not shipping desired files. For example, if you want to include the file a/b/c.txt but your VCS ignores a/b, the file c.txt will not be seen because its parent directory will not be entered. In such cases you can use the force-include option.

Reproducible builds

By default, build targets will build in a reproducible manner provided that they support that behavior. To disable this, set reproducible to false:

[tool.hatch.build]
reproducible = false
[build]
reproducible = false

When enabled, the SOURCE_DATE_EPOCH environment variable will be used for all build timestamps. If not set, then Hatch will use an unchanging default value.

Output directory

When the output directory is not provided to the build command, the dist directory will be used by default. You can change the default to a different directory using a relative or absolute path like so:

[tool.hatch.build]
directory = "<PATH>"
[build]
directory = "<PATH>"

Dev mode

By default for dev mode environment installations or editable installs, the wheel target will determine which directories should be added to Python's search path based on the selected files.

If you want to override this detection or perhaps instruct other build targets as well, you can use the dev-mode-dirs option:

[tool.hatch.build]
dev-mode-dirs = ["."]
[build]
dev-mode-dirs = ["."]

If you don't want to add entire directories to Python's search path, you can enable a more targeted mechanism with the mutually exclusive dev-mode-exact option:

[tool.hatch.build]
dev-mode-exact = true
[build]
dev-mode-exact = true

Warning

The dev-mode-exact mechanism is not supported by static analysis tools & IDEs, therefore functionality such as autocompletion is unlikely to work.

Build targets

A build target can be provided by any builder plugin. There are three built-in build targets: wheel, sdist, and custom.

Dependencies

You can specify additional dependencies that will be installed in each build environment, such as for third party builders:

[tool.hatch.build.targets.your-target-name]
dependencies = [
  "your-builder-plugin"
]
[build.targets.your-target-name]
dependencies = [
  "your-builder-plugin"
]

You can also declare dependence on the project's runtime dependencies with the require-runtime-dependencies option:

[tool.hatch.build.targets.your-target-name]
require-runtime-dependencies = true
[build.targets.your-target-name]
require-runtime-dependencies = true

Additionally, you may declare dependence on specific runtime features of the project with the require-runtime-features option:

[tool.hatch.build.targets.your-target-name]
require-runtime-features = [
  "feature1",
  "feature2",
]
[build.targets.your-target-name]
require-runtime-features = [
  "feature1",
  "feature2",
]

Versions

If a build target supports multiple build strategies or if there are major changes over time, you can specify exactly which versions you want to build using the versions option, which may be defined as either an array of strings or a comma-separated string:

[tool.hatch.build.targets.<TARGET_NAME>]
versions = [
  "v1",
  "beta-feature",
]
[build.targets.<TARGET_NAME>]
versions = [
  "v1",
  "beta-feature",
]

See the wheel target for a real world example.

Build hooks

A build hook defines code that will be executed at various stages of the build process and can be provided by any build hook plugin. There is one built-in build hook: custom.

Build hooks can be applied either globally:

[tool.hatch.build.hooks.<HOOK_NAME>]
[build.hooks.<HOOK_NAME>]

or to specific build targets:

[tool.hatch.build.targets.<TARGET_NAME>.hooks.<HOOK_NAME>]
[build.targets.<TARGET_NAME>.hooks.<HOOK_NAME>]

Dependencies

You can specify additional dependencies that will be installed in each build environment, such as for third party build hooks:

[tool.hatch.build.hooks.your-hook-name]
dependencies = [
  "your-build-hook-plugin"
]
[build.hooks.your-hook-name]
dependencies = [
  "your-build-hook-plugin"
]

You can also declare dependence on the project's runtime dependencies with the require-runtime-dependencies option:

[tool.hatch.build.hooks.your-hook-name]
require-runtime-dependencies = true
[build.hooks.your-hook-name]
require-runtime-dependencies = true

Additionally, you may declare dependence on specific runtime features of the project with the require-runtime-features option:

[tool.hatch.build.hooks.your-hook-name]
require-runtime-features = [
  "feature1",
  "feature2",
]
[build.hooks.your-hook-name]
require-runtime-features = [
  "feature1",
  "feature2",
]

Order of execution

For each build target, build hooks execute in the order in which they are defined, starting with global hooks.

As an example, for the following configuration:

[tool.hatch.build.targets.foo.hooks.hook2]

[tool.hatch.build.hooks.hook3]
[tool.hatch.build.hooks.hook1]
[build.targets.foo.hooks.hook2]

[build.hooks.hook3]
[build.hooks.hook1]

When target foo is built, build hook hook3 will be executed first, followed by hook1, and then finally hook2.

Conditional execution

If you want to disable a build hook by default and control its use by environment variables, you can do so by setting the enable-by-default option to false:

[tool.hatch.build.hooks.<HOOK_NAME>]
enable-by-default = false
[build.hooks.<HOOK_NAME>]
enable-by-default = false

Environment variables

Variable Default Description
HATCH_BUILD_CLEAN false Whether or not existing artifacts should first be removed
HATCH_BUILD_CLEAN_HOOKS_AFTER false Whether or not build hook artifacts should be removed after each build
HATCH_BUILD_HOOKS_ONLY false Whether or not to only execute build hooks
HATCH_BUILD_NO_HOOKS false Whether or not to disable all build hooks; this takes precedence over other options
HATCH_BUILD_HOOKS_ENABLE false Whether or not to enable all build hooks
HATCH_BUILD_HOOK_ENABLE_<HOOK_NAME> false
HATCH_BUILD_LOCATION dist The location with which to build the targets; only used by the build command

Last update: September 14, 2022