Dependencies are recorded to a text file that is catted at the end.
This should prevent subtle bugs like https://bugzilla.redhat.com/2183519 in the future.
Related: rhbz#2208971
When the build backend prints to stdout via non-Python means,
for example when a setup.py script calls a verbose program via os.system(),
the output leaked to stdout of %pyproject_buildrequires was treated as generated BuildRequires.
Fore example, if the setup.py script has:
rv = os.system('/usr/bin/patch -N -p3 -d build/lib < lib/py-lmdb/env-copy-txn.patch')
(From https://github.com/jnwatson/py-lmdb/blob/py-lmdb_1.0.0/setup.py#L117)
The stdout of /usr/bin/patch leaked to stdout of %pyproject_buildrequires:
[lmdb-1.0.0]$ /usr/bin/python3 -Bs /usr/lib/rpm/redhat/pyproject_buildrequires.py --python3_pkgversion 3 2>/dev/null
python3dist(setuptools) >= 40.8
python3dist(wheel)
patching file lmdb.h
patching file mdb.c
python3dist(wheel)
patching file lmdb.h
patching file mdb.c
This resulted in DNF errors like this:
No matching package to install: 'lmdb.h'
No matching package to install: 'mdb.c'
No matching package to install: 'patching'
Moreover, it resulted in bogus BuildRequires that may have existed (e.g. "file").
By replacing the usage of contextlib.redirect_stdout
(which only redirects Python's sys.stdout)
with a custom context manager that captures stdout on file descriptor level
(in addition to Python's sys.stdout),
we avoid this leak.
File descriptor magic heavily inspired by the capfd pytest fixture.
Related: rhbz#2168193
The hook is optional, see https://www.python.org/dev/peps/pep-0517/#prepare-metadata-for-build-wheel
> If a build frontend needs this information and the method is not defined,
> it should call build_wheel and look at the resulting metadata directly.
This is not yet automatically detected because the feature is provisional.
Use `%pyproject_buildrequires -w` to opt-in.
Resolves: rhbz#2060109
Improve handling of > operator, preventing post-release from satisfying most rpm requirements.
Improve handling of < operator, preventing pre-release from satisfying rpm requirement.
Improve handling of != operator with prefix matching, preventing pre-release from satisfying rpm requirements.
Related: rhbz#1950291
%pyproject_buildrequires macro now accepts multiple file names to load
additional dependencies from them.
New option -N was added to disable automatical generation of requirements
in case package does not use build system. Option -N cannot be used in
combination with options -r, -e, -t, -x.
Co-authored-by: Miro Hrončok <miro@hroncok.cz>
Related: rhbz#1950291
