AttributeError: 'Compiler' object has no attribute 'dry_run' when installing with setuptools >= v81.0.0 #485
Description
Setuptools deprecated the --dry-run flag on 6 February 2026 in the v81.0.0 release:
pkg_resources has been removed from Setuptools. Most common uses of pkg_resources have been superseded by the importlib.resources and importlib.metadata projects. Projects and environments relying on pkg_resources for namespace packages or other behavior should depend on older versions of setuptools. (#3085)
This leads to:
docker run --rm -it python:3.9-slim pip install projectq
Collecting projectq
[... snipped ... ]
× Building wheel for projectq (pyproject.toml) did not run successfully.
│ exit code: 1
╰─> [494 lines of output]
/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/config/_apply_pyprojecttoml.py:82: SetuptoolsDeprecationWarning: `project.license` as a TOML table is deprecated
!!
********************************************************************************
Please use a simple string containing a SPDX expression for `project.license`. You can also use `project.license-files`. (Both options available on setuptools>=77.0.0).
By 2027-Feb-18, you need to update your project and remove deprecated calls
or your builds will no longer be supported.
See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
********************************************************************************
!!
corresp(dist, value, root_dir)
/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/config/_apply_pyprojecttoml.py:61: SetuptoolsDeprecationWarning: License classifiers are deprecated.
!!
********************************************************************************
Please consider removing the following classifiers in favor of a SPDX license expression:
License :: OSI Approved :: Apache Software License
See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
********************************************************************************
!!
dist._finalize_license_expression()
/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/dist.py:765: SetuptoolsDeprecationWarning: License classifiers are deprecated.
!!
********************************************************************************
Please consider removing the following classifiers in favor of a SPDX license expression:
License :: OSI Approved :: Apache Software License
See https://packaging.python.org/en/latest/guides/writing-pyproject-toml/#license for details.
********************************************************************************
!!
self._finalize_license_expression()
[... snipped ... ]
/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/command/build_py.py:215: _Warning: Package 'projectq.backends._sim._cppkernels' is absent from the `packages` configuration.
!!
********************************************************************************
############################
# Package would be ignored #
############################
Python recognizes 'projectq.backends._sim._cppkernels' as an importable package[^1],
but it is absent from setuptools' `packages` configuration.
This leads to an ambiguous overall configuration. If you want to distribute this
package, please make sure that 'projectq.backends._sim._cppkernels' is explicitly added
to the `packages` configuration field.
Alternatively, you can also rely on setuptools' discovery methods
(for example by using `find_namespace_packages(...)`/`find_namespace:`
instead of `find_packages(...)`/`find:`).
You can read more about "package discovery" on setuptools documentation page:
- https://setuptools.pypa.io/en/latest/userguide/package_discovery.html
If you don't want 'projectq.backends._sim._cppkernels' to be distributed and are
already explicitly excluding 'projectq.backends._sim._cppkernels' via
`find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
you can try to use `exclude_package_data`, or `include-package-data=False` in
combination with a more fine grained `package-data` configuration.
You can read more about "package data files" on setuptools documentation page:
- https://setuptools.pypa.io/en/latest/userguide/datafiles.html
[^1]: For Python, any directory (with suitable naming) can be imported,
even if it does not contain any `.py` files.
On the other hand, currently there is no concept of package data
directory, all directories are treated like packages.
********************************************************************************
!!
check.warn(importable)
/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/command/build_py.py:215: _Warning: Package 'projectq.backends._sim._cppkernels.intrin' is absent from the `packages` configuration.
!!
********************************************************************************
############################
# Package would be ignored #
############################
Python recognizes 'projectq.backends._sim._cppkernels.intrin' as an importable package[^1],
but it is absent from setuptools' `packages` configuration.
This leads to an ambiguous overall configuration. If you want to distribute this
package, please make sure that 'projectq.backends._sim._cppkernels.intrin' is explicitly added
to the `packages` configuration field.
Alternatively, you can also rely on setuptools' discovery methods
(for example by using `find_namespace_packages(...)`/`find_namespace:`
instead of `find_packages(...)`/`find:`).
You can read more about "package discovery" on setuptools documentation page:
- https://setuptools.pypa.io/en/latest/userguide/package_discovery.html
If you don't want 'projectq.backends._sim._cppkernels.intrin' to be distributed and are
already explicitly excluding 'projectq.backends._sim._cppkernels.intrin' via
`find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
you can try to use `exclude_package_data`, or `include-package-data=False` in
combination with a more fine grained `package-data` configuration.
You can read more about "package data files" on setuptools documentation page:
- https://setuptools.pypa.io/en/latest/userguide/datafiles.html
[^1]: For Python, any directory (with suitable naming) can be imported,
even if it does not contain any `.py` files.
On the other hand, currently there is no concept of package data
directory, all directories are treated like packages.
********************************************************************************
!!
check.warn(importable)
/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/command/build_py.py:215: _Warning: Package 'projectq.backends._sim._cppkernels.nointrin' is absent from the `packages` configuration.
!!
********************************************************************************
############################
# Package would be ignored #
############################
Python recognizes 'projectq.backends._sim._cppkernels.nointrin' as an importable package[^1],
but it is absent from setuptools' `packages` configuration.
This leads to an ambiguous overall configuration. If you want to distribute this
package, please make sure that 'projectq.backends._sim._cppkernels.nointrin' is explicitly added
to the `packages` configuration field.
Alternatively, you can also rely on setuptools' discovery methods
(for example by using `find_namespace_packages(...)`/`find_namespace:`
instead of `find_packages(...)`/`find:`).
You can read more about "package discovery" on setuptools documentation page:
- https://setuptools.pypa.io/en/latest/userguide/package_discovery.html
If you don't want 'projectq.backends._sim._cppkernels.nointrin' to be distributed and are
already explicitly excluding 'projectq.backends._sim._cppkernels.nointrin' via
`find_namespace_packages(...)/find_namespace` or `find_packages(...)/find`,
you can try to use `exclude_package_data`, or `include-package-data=False` in
combination with a more fine grained `package-data` configuration.
You can read more about "package data files" on setuptools documentation page:
- https://setuptools.pypa.io/en/latest/userguide/datafiles.html
[^1]: For Python, any directory (with suitable naming) can be imported,
even if it does not contain any `.py` files.
On the other hand, currently there is no concept of package data
directory, all directories are treated like packages.
********************************************************************************
!!
[... snipped ... ]
running build_ext
Traceback (most recent call last):
File "/usr/local/lib/python3.9/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 353, in <module>
main()
File "/usr/local/lib/python3.9/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 335, in main
json_out['return_val'] = hook(**hook_input['kwargs'])
File "/usr/local/lib/python3.9/site-packages/pip/_vendor/pyproject_hooks/_in_process/_in_process.py", line 251, in build_wheel
return _build_backend().build_wheel(wheel_directory, config_settings,
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 441, in build_wheel
return _build(['bdist_wheel', '--dist-info-dir', str(metadata_directory)])
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 429, in _build
return self._build_with_temp_dir(
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 410, in _build_with_temp_dir
self.run_setup()
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/build_meta.py", line 317, in run_setup
exec(code, locals())
File "<string>", line 775, in <module>
File "<string>", line 747, in run_setup
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/__init__.py", line 117, in setup
return distutils.core.setup(**attrs) # type: ignore[return-value]
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/core.py", line 186, in setup
return run_commands(dist)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/core.py", line 202, in run_commands
dist.run_commands()
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 1000, in run_commands
self.run_command(cmd)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 1107, in run_command
super().run_command(command)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 1019, in run_command
cmd_obj.run()
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/command/bdist_wheel.py", line 370, in run
self.run_command("build")
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/cmd.py", line 341, in run_command
self.distribution.run_command(command)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 1107, in run_command
super().run_command(command)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 1019, in run_command
cmd_obj.run()
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/command/build.py", line 135, in run
self.run_command(cmd_name)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/cmd.py", line 341, in run_command
self.distribution.run_command(command)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/dist.py", line 1107, in run_command
super().run_command(command)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/dist.py", line 1019, in run_command
cmd_obj.run()
File "<string>", line 336, in run
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/command/build_ext.py", line 97, in run
_build_ext.run(self)
File "/tmp/pip-build-env-b03e9_xu/overlay/lib/python3.9/site-packages/setuptools/_distutils/command/build_ext.py", line 367, in run
self.build_extensions()
File "<string>", line 342, in build_extensions
File "<string>", line 415, in _configure_compiler
AttributeError: 'Compiler' object has no attribute 'dry_run'
[end of output]
note: This error originates from a subprocess, and is likely not a problem with pip.
ERROR: Failed building wheel for projectq
Failed to build projectq
ERROR: Could not build wheels for projectq, which is required to install pyproject.toml-based projects
This doesn't happen with python3.8, but fails with python >= 3.9.