Bug 1976459

Summary:	%pyproject_buildrequires should only fallback to setuptools.build_meta:__legacy__ if setup.py exists
Product:	[Fedora] Fedora	Reporter:	Miro Hrončok <mhroncok>
Component:	pyproject-rpm-macros	Assignee:	Tomáš Hrnčiar <thrnciar>
Status:	CLOSED ERRATA	QA Contact:	Fedora Extras Quality Assurance <extras-qa>
Severity:	unspecified	Docs Contact:
Priority:	unspecified
Version:	rawhide	CC:	mhroncok, pviktori, python-sig
Target Milestone:	---	Keywords:	Reopened
Target Release:	---
Hardware:	Unspecified
OS:	Unspecified
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Fixed In Version:	pyproject-rpm-macros-0-44.fc35 pyproject-rpm-macros-0-46.fc34 pyproject-rpm-macros-0-46.fc33	Doc Type:	If docs needed, set a value
Doc Text:		Story Points:	---
Clone Of:		Environment:
Last Closed:	2021-08-02 01:03:18 UTC	Type:	Bug
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oVirt Team:	---	RHEL 7.3 requirements from Atomic Host:
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Embargoed:

Description Miro Hrončok 2021-06-26 09:53:16 UTC

See https://github.com/pypa/pip/pull/10031 and https://github.com/pypa/build/issues/259

The common PEP 517 backends (pip, build) interpret this part of PEP 517:

"""
If the pyproject.toml file is absent, or the build-backend key is missing, the source tree is not using this specification, and tools should revert to the legacy behaviour of running setup.py (either directly, or by implicitly invoking the setuptools.build_meta:__legacy__ backend).
"""

As "...should revert to the legacy behavior by running setup.py directly or running setup.py via the setuptools.build_meta:__legacy__ backend."

Since we invoke pip in %pyproject_wheel, we follow the same logic as pip. 

However, %pyproject_buildrequires currently invokes the setuptools.build_meta:__legacy__ backend even if setup.py is missing, which will lead to successful %generate_buildrequires but failed %build (at least with pip >= 21.1.3).

With older pips, it may even lead to installing a Python project called UNKNOWN, see https://github.com/pypa/setuptools/issues/2329


I propose we deal with this by mimicking pip's behavior in %pyproject_buildrequires -- if pyproject.toml is missing or doe snot specify the build backend, we fallback to setuptools.build_meta:__legacy__ *only if* setup.py is present, and error otherwise. For reference, the pip's error message is 'File "setup.py" not found for legacy project {requirement/path/link/...}.'

Comment 1 Miro Hrončok 2021-07-17 23:51:35 UTC

Merged in https://src.fedoraproject.org/rpms/pyproject-rpm-macros/pull-request/183

Comment 2 Fedora Update System 2021-07-19 07:59:04 UTC

FEDORA-2021-fe1bbcfd07 has been submitted as an update to Fedora 35. https://bodhi.fedoraproject.org/updates/FEDORA-2021-fe1bbcfd07

Comment 3 Fedora Update System 2021-07-19 08:01:22 UTC

FEDORA-2021-9874c0ec7b has been submitted as an update to Fedora 34. https://bodhi.fedoraproject.org/updates/FEDORA-2021-9874c0ec7b

Comment 4 Fedora Update System 2021-07-19 08:01:23 UTC

FEDORA-2021-ffa81019cf has been submitted as an update to Fedora 33. https://bodhi.fedoraproject.org/updates/FEDORA-2021-ffa81019cf

Comment 5 Fedora Update System 2021-07-19 08:01:35 UTC

FEDORA-2021-fe1bbcfd07 has been pushed to the Fedora 35 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 6 Fedora Update System 2021-07-20 01:01:18 UTC

FEDORA-2021-ffa81019cf has been pushed to the Fedora 33 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-ffa81019cf`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-ffa81019cf

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 7 Fedora Update System 2021-07-20 01:47:14 UTC

FEDORA-2021-9874c0ec7b has been pushed to the Fedora 34 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-9874c0ec7b`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-9874c0ec7b

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 8 Fedora Update System 2021-07-24 01:18:20 UTC

FEDORA-2021-fcf5e2adc6 has been pushed to the Fedora 34 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-fcf5e2adc6`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-fcf5e2adc6

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 9 Fedora Update System 2021-07-24 01:24:58 UTC

FEDORA-2021-3d06d86fe9 has been pushed to the Fedora 33 testing repository.
Soon you'll be able to install the update with the following command:
`sudo dnf upgrade --enablerepo=updates-testing --advisory=FEDORA-2021-3d06d86fe9`
You can provide feedback for this update here: https://bodhi.fedoraproject.org/updates/FEDORA-2021-3d06d86fe9

See also https://fedoraproject.org/wiki/QA:Updates_Testing for more information on how to test updates.

Comment 10 Fedora Update System 2021-08-02 01:03:18 UTC

FEDORA-2021-fcf5e2adc6 has been pushed to the Fedora 34 stable repository.
If problem still persists, please make note of it in this bug report.

Comment 11 Fedora Update System 2021-08-02 01:06:12 UTC

FEDORA-2021-3d06d86fe9 has been pushed to the Fedora 33 stable repository.
If problem still persists, please make note of it in this bug report.