conda-build abi3 with C++ binaries incorrectly detected as build scripts

[larsoner]

Checklist

• I added a descriptive title
• I searched open reports and couldn't find a duplicate

What happened?

See conda-forge/openmeeg-feedstock#77 (comment), adapting from there:

The openmeeg feedstock produces several C++ executables such as om_mesh_smooth, plus a Python library that (SWIG-)wraps to some shared libraries. I'm trying to move this package to abi3, but I'm getting:

conda_build.exceptions.CondaBuildUserError: Noarch package contains binary script: om_mesh_smooth

This is a binary C++ executable, not a Python script. Is there some way to get it to ignore these when iterating in rewrite_script in conda-build?

@isuruf suggested I open an issue here about this since it seems like there isn't a way to do this currently.

I'm going to skip all the conda info etc. below since it's all part of the standard conda-forge feedstock infrastructure as of today (2026 June 9), and should be accessible at least for a while in the action run above.

[jaimergp]

Full traceback:

Traceback (most recent call last):
  File "/opt/conda/lib/python3.12/site-packages/conda_build/noarch_python.py", line 29, in rewrite_script
    data = src.read_text(encoding=encoding)
           ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/conda/lib/python3.12/pathlib.py", line 1028, in read_text
    return f.read()
           ^^^^^^^^
  File "<frozen codecs>", line 322, in decode
UnicodeDecodeError: 'utf-8' codec can't decode byte 0xc0 in position 24: invalid start byte

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/opt/conda/bin/conda-build", line 10, in <module>
    sys.exit(execute())
             ^^^^^^^^^
  File "/opt/conda/lib/python3.12/site-packages/conda_build/cli/main_build.py", line 639, in execute
    api.build(
  File "/opt/conda/lib/python3.12/site-packages/conda_build/api.py", line 214, in build
    return build_tree(
           ^^^^^^^^^^^
  File "/opt/conda/lib/python3.12/site-packages/conda_build/build.py", line 3687, in build_tree
    packages_from_this = build(
                         ^^^^^^
  File "/opt/conda/lib/python3.12/site-packages/conda_build/build.py", line 2798, in build
    newly_built_packages = bundlers[pkg_type](
                           ^^^^^^^^^^^^^^^^^^^
  File "/opt/conda/lib/python3.12/site-packages/conda_build/build.py", line 1899, in bundle_conda
    files = post_process_files(metadata, initial_files)
            ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/conda/lib/python3.12/site-packages/conda_build/build.py", line 1696, in post_process_files
    noarch_python.populate_files(m, pkg_files, host_prefix, [])
  File "/opt/conda/lib/python3.12/site-packages/conda_build/noarch_python.py", line 95, in populate_files
    handle_file(f, d, prefix)
  File "/opt/conda/lib/python3.12/site-packages/conda_build/noarch_python.py", line 76, in handle_file
    fn = rewrite_script(fn, prefix)
         ^^^^^^^^^^^^^^^^^^^^^^^^^^
  File "/opt/conda/lib/python3.12/site-packages/conda_build/noarch_python.py", line 31, in rewrite_script
    raise CondaBuildUserError(f"Noarch package contains binary script: {fn}")
conda_build.exceptions.CondaBuildUserError: Noarch package contains binary script: om_mesh_smooth

Full logs: logs.txt