flit-scm-py fails to build with LookupError: setuptools-scm was unable to detect version

[dhomeier]

Full traceback

PYTHONPATH=/opt/sw4/share/bootstrap-modules-python310 /opt/sw4/bin/python3.10 -m build --wheel --no-isolation --skip-dependency-check
* Building wheel...
Traceback (most recent call last):
  File "/opt/sw4/share/bootstrap-modules-python310/pyproject_hooks/_in_process/_in_process.py", line 373, in <module>
    main()
  File "/opt/sw4/share/bootstrap-modules-python310/pyproject_hooks/_in_process/_in_process.py", line 357, in main
    json_out["return_val"] = hook(**hook_input["kwargs"])
  File "/opt/sw4/share/bootstrap-modules-python310/pyproject_hooks/_in_process/_in_process.py", line 271, in build_wheel
    return _build_backend().build_wheel(
  File "/opt/sw4/share/bootstrap-modules-python310/pyproject_hooks/_in_process/_in_process.py", line 70, in _build_backend
    obj = import_module(mod_path)
  File "/opt/sw4/lib/python3.10/importlib/__init__.py", line 126, in import_module
    return _bootstrap._gcd_import(name[level:], package, level)
  File "<frozen importlib._bootstrap>", line 1050, in _gcd_import
  File "<frozen importlib._bootstrap>", line 1027, in _find_and_load
  File "<frozen importlib._bootstrap>", line 1006, in _find_and_load_unlocked
  File "<frozen importlib._bootstrap>", line 688, in _load_unlocked
  File "<frozen importlib._bootstrap_external>", line 883, in exec_module
  File "<frozen importlib._bootstrap>", line 241, in _call_with_frames_removed
  File "/opt/sw4/src/fink.build/flit-scm-py310-1.7.0-1/flit_scm-1.7.0/flit_scm/__init__.py", line 21, in <module>
    get_version(**setuptools_scm_config)
  File "/opt/sw4/share/bootstrap-modules-python310/setuptools_scm/__init__.py", line 148, in get_version
    _version_missing(config)
  File "/opt/sw4/share/bootstrap-modules-python310/setuptools_scm/__init__.py", line 108, in _version_missing
    raise LookupError(
LookupError: setuptools-scm was unable to detect version for /opt/sw4/src/fink.build/flit-scm-py310-1.7.0-1/flit_scm-1.7.0.

Make sure you're either building from a fully intact git repository or PyPI tarballs. Most other sources (such as GitHub's tarballs, a git checkout without the .git folder) don't contain the necessary metadata and will not work.

For example, if you're using pip, instead of https://github.com/user/proj/archive/master.zip use git+https://github.com/user/proj.git#egg=proj

ERROR Backend subprocess exited when trying to invoke build_wheel

The error message seems quite nonsensical since this is the PyPI tarball, with a complete PKG-INFO and current flit_scm/._version.py in fact. As the last update upstream was "support setuptools_scm >= 6.4", I have also tried downgrading those from 7.1.0 to 6.4.2, but with the same failure.
Running from setuptools_scm import get_version; get_version() directly in the source dir produces the same result; it's totally unclear to me why the package tries to enforce getting a setuptools_scm version when the _version.py file already exists...

bootstrap-modules-py310 20241126-2
Package manager version: 0.45.99.git
Distribution version: selfupdate-point (bootstrap), 15.0, arm64
Trees: local/main stable/main
Xcode.app: 16.2
Xcode command-line tools: 16.2.0.0.1.1733547573
Max. Fink build jobs: 8

[dhomeier]

I could get the wheel build and install to work by removing the [tool.setuptools_scm] section from pyproject.toml, which lets it pass onto using the existing flit_scm/_version.py.

[nieder]

I got nothing. My only suggestion would have been to downgrade setuptools-scm, but you already tried that.

[dhomeier]

With what Python and Distribution does it build for you?
My guess was that the source package uploaded to PyPI is broken, but installing directly from there with pip install --no-build-isolation --no-binary builds the wheel successfully; unfortunately I could not get pip to echo exactly what commands it's using for that.

[nieder]

This is on 10.14.6

nieder $ ls -l flit-scm-py3*
-rw-r--r--  1 root  wheel  4764 Jul  1  2023 flit-scm-py310_1.7.0-1_darwin-x86_64.deb
-rw-r--r--  1 root  wheel  4732 Feb  9  2024 flit-scm-py37_1.7.0-1_darwin-x86_64.deb
-rw-r--r--  1 root  wheel  4736 Jul  1  2023 flit-scm-py38_1.7.0-1_darwin-x86_64.deb
-rw-r--r--  1 root  wheel  4758 Jul  1  2023 flit-scm-py39_1.7.0-1_darwin-x86_64.deb

So I was able to build it 1.5 years ago. And trying now also succeeds on py38 but fails on py310:

flit_scm-1.7.0/pyproject.toml
flit_scm-1.7.0/PKG-INFO
sudo -u fink-bld [ENV] sh -c /tmp/fink.ksajQ
PYTHONPATH=/sw/share/bootstrap-modules-python38 /sw/bin/python3.8 -m build --wheel --no-isolation --skip-dependency-check
* Building wheel...
Successfully built flit_scm-1.7.0-py3-none-any.whl
phase test: passed
/bin/rm -rf /sw/build.build/root-flit-scm-py38-1.7.0-1
/bin/mkdir -p /sw/build.build/root-flit-scm-py38-1.7.0-1/sw
/bin/mkdir -p /sw/build.build/root-flit-scm-py38-1.7.0-1/DEBIAN

I recently uninstalled all my py310 mods for testing, so there's a lot more junk in my py38 install that could be a missing BDep.

[nieder]

py37 also fails for me.

Then testing things, if I have bootstrap-modules-py310-20241126-2 (latest), py310 fails. If I downgrade to 20241126-1 (or any of the 20221003 debs) it works.

The changes between 20241126-1 and 20241126-2 are things like this, with versioning added to the dist-info directory when needed.

-    5141 2024-11-28 06:03 ./sw/share/bootstrap-modules-python310/pyparsing.dist-info/METADATA
+    5141 2024-12-04 04:31 ./sw/share/bootstrap-modules-python310/pyparsing-3.1.4.dist-info/METADATA

I would think that helps builds...

[dhomeier]

I confirm that building the py38 and py39 versions succeeds with bootstrap-modules-py3N-20241126-2 installed.
py310 still fails after downgrading to bootstrap-modules-py310-20241126-1, but builds with 20221003-3 or earlier.

[nieder]

This makes me think that there's some interplay between unknown pymods affecting the version detection. flit-scm has fairly simple dependencies: https://gitlab.com/WillDaSilva/flit_scm/-/blob/main/pyproject.toml?ref_type=heads#L35-39

I do notice that it calls for flit-core ~= 3.5, while ours is currently at 3.9.0 both in standalone and in bootstrap-modules. However, the 20221103 bootstrap-modules was at flit-core=3.7.1, which technically also doesn't satisfy the upsteam ~=3.5 requires.

[dhomeier]

I do notice that it calls for flit-core ~= 3.5, while ours is currently at 3.9.0 both in standalone and in bootstrap-modules. However, the 20221103 bootstrap-modules was at flit-core=3.7.1, which technically also doesn't satisfy the upsteam ~=3.5 requires.

The pip install specifies flit-core ~= 3.5 as well, yet is building successfully with 3.10 installed.

Other datapoints with bootstrap-modules >= 20241126:

• building exceptiongroup-py310 fails with a similar LookupError with either patched or unpatched flit-scm as well
• pytest-7.4.4 fails on

`bdist_wheel` [no longer]

> PYTHONPATH=/opt/sw4/share/bootstrap-modules-python310 /opt/sw4/bin/python3.10 -m build --wheel --no-isolation --skip-dependency-check > Building wheel... usage: _in_process.py [global_opts] cmd1 [cmd1_opts] [cmd2 [cmd2_opts] ...] or: _in_process.py --help [cmd1 cmd2 ...] or: _in_process.py --help-commands or: _in_process.py cmd --help

error: invalid command 'bdist_wheel'

ERROR Backend subprocess exited when trying to invoke build_wheel

[nieder]

The bdist_wheel problem should have been taken care of by 9a745e0

[dhomeier]

Right; I had previously rebuilt bootstrap-modules to the prior commit, which had the same revision. With the entry_points.txt included, pytest build succeeds, but the same failure on exceptiongroup.