uv itself is a large package with many dependencies and lots of
features. To build a package using the uv build backend, you shouldn't
have to download and install the entirety of uv. For platform where we
don't provide wheels, it should be possible and fast to compile the uv
build backend. To that end, we're introducing a python package that
contains a trimmed down version of uv that only contains the build
backend, with a minimal dependency tree in rust.
The `uv_build` package is publish from CI just like uv itself. It is
part of the workspace, but has much less dependencies for its own
binary. We're using cargo deny to enforce that the network stack is not
part of the dependencies. A new build profile ensure we're getting the
minimum possible binary size for a rust binary.
---------
Co-authored-by: Zanie Blue <contact@zanie.dev>
First of all, I want to test automatic managed installs (see #10913) and
need to set that up. Second of all, some tests were _implicitly_
downloading interpreters instead of using the one from their context —
which is unexpected and naughty and very slow.
When adding excludes, we usually don't want to include python cache
files. On the contrary, I haven't seen any project in my ecosystem
research that would want any of `__pycache__`, `*.pyc`, `*.pyo` to be
included. By moving them behind a `default-excludes` toggle, they are
always active even when defining custom excludes, but can be deactivated
if the user so chooses.
With includes and excludes being this small again, we can roll back the
include-exclude anchored difference to always using anchored globs (i.e.
you would need to use `**/build-*.h` below).
A pyproject.toml with custom settings with the change applied:
```toml
[project]
name = "foo"
version = "0.1.0"
readme = "README.md"
license-files = ["LICENSE*", "third-party-licenses/*"]
[tool.uv.build-backend]
# A file we need for the source dist -> wheel step, but not in the wheel itself (currently unused)
source-include = ["data/build-script.py"]
# A temporary or generated file we want to ignore
source-exclude = ["/src/foo/not-packaged.txt"]
# Headers are build-only
wheel-exclude = ["build-*.h"]
[tool.uv.build-backend.data]
scripts = "scripts"
data = "assets"
headers = "header"
[build-system]
requires = ["uv>=0.5.5,<0.6"]
build-backend = "uv"
```
When building the source distribution, we always need to include
`pyproject.toml` and the module, when building the wheel, we always
include the module but nothing else at top level. Since we only allow a
single module per wheel, that means that there are no specific wheel
includes. This means we have source includes, source excludes, wheel
excludes, but no wheel includes: This is defined by the module root,
plus the metadata files and data directories separately.
Extra source dist includes are currently unused (they can't end up in
the wheel currently), but it makes sense to model them here, they will
be needed for any sort of procedural build step.
This results in the following fields being relevant for inclusions and
exclusion:
* `pyproject.toml` (always included in the source dist)
* project.readme: PEP 621
* project.license-files: PEP 639
* module_root: `Path`
* source_include: `Vec<Glob>`
* source_exclude: `Vec<Glob>`
* wheel_exclude: `Vec<Glob>`
* data: `Map<KnownDataName, Path>`
An opinionated choice is that that wheel excludes always contain the
source excludes: Otherwise you could have a path A in the source tree
that gets included when building the wheel directly from the source
tree, but not when going through the source dist as intermediary,
because A is in source excludes, but not in the wheel excludes. This has
been a source of errors previously.
In the process, I fixed a bug where we would skip directories and only
include the files and were missing license due to absolute globs.
Allow including data files in wheels, configured through
`pyproject.toml`. This configuration is currently only read in the build
backend. We'd only start using it in the frontend when we're adding a
fast path.
Each data entry is a directory, whose contents are copied to the
matching directory in the wheel in
`<name>-<version>.data/(purelib|platlib|headers|scripts|data)`. Upon
installation, this data is moved to its target location, as defined by
<https://docs.python.org/3.12/library/sysconfig.html#installation-paths>:
- `data`: Installed over the virtualenv environment root. Warning: This
may override existing files!
- `scripts`: Installed to the directory for executables, `<venv>/bin` on
Unix or `<venv>\Scripts` on Windows. This directory is added to PATH
when the virtual environment is activated or when using `uv run`, so
this data type can be used to install additional binaries. Consider
using `project.scripts` instead for starting Python code.
- `headers`: Installed to the include directory, where compilers
building Python packages with this package as built requirement will
search for header files.
- `purelib` and `platlib`: Installed to the `site-packages` directory.
It is not recommended to uses these two options.
For simplicity, for now we're just defining a directory to be copied for
each data directory, while using the glob based include mechanism in the
background. We thereby introduce a third mechanism next to the main
includes and the PEP 639 mechanism, which is not what we should finalize
on.
When building source distributions, we need to include the readme, so it
can become part the METADATA body when building the wheel. We also need
to support the license files from PEP 639. When building the source
distribution, we copy those file relative to their origin, when building
the wheel, we copy them to `.dist-info/licenses`.
The test for idempotence in wheel building is merged into the file
listing test, which also covers that source tree -> source dist -> wheel
is equivalent to source tree -> wheel, though we do need to check for
file inclusion stronger here.
Best reviewed commit-by-commit
A first milestone: source tree -> source dist -> wheel -> install works.
This PR adds a test for this.
There's obviously a lot still missing, including basics such as the
Readme inclusion.
