Getting "ValueError: Mixing meta.yaml and recipe.yaml recipes is not supported" in PR with only meta.yaml

[BioGeek]

Bug:

In PR #29827 up until commit 50f6bf6 the Linux and macOs builds were working and the Windows build was failing as expected (because torchaudio is not availble on that platform).

Then from commit 116f63c all my builds suddenly start failing with:

Building all recipes
+ echo 'Building all recipes'
+ python /home/conda/staged-recipes-copy/.ci_support/build_all.py
/home/conda/staged-recipes-copy/.ci_support/compute_build_graph.py:37: UserWarning: pkg_resources is deprecated as an API. See https://setuptools.pypa.io/en/latest/pkg_resources.html. The pkg_resources package is slated for removal as early as 2025-11-30. Refrain from using this package or pin to Setuptools<81.
  import pkg_resources
Traceback (most recent call last):
  File "/home/conda/staged-recipes-copy/.ci_support/build_all.py", line 387, in <module>
    build_all(os.path.join(root_dir, "recipes"), args.arch)
  File "/home/conda/staged-recipes-copy/.ci_support/build_all.py", line 109, in build_all
    raise ValueError("Mixing meta.yaml and recipe.yaml recipes is not supported")
ValueError: Mixing meta.yaml and recipe.yaml recipes is not supported

which doesn't make sense because there is only a meta.yaml in my PR.

@conda-forge-admin, please ping conda-forge/staged-recipes