After much delibration about how in-place test builds should work, I have pulled out all of the text extension code from setup.py into a new build_tests.py and updated Makefile.am to invoke it. This replaces the old `python3 setup.py build_ext --inplace` with enough setuptools tooling to replicate that behaviour, while also putting it in a better place to avoid problems arising from the deprecation of direct setup.py invocation [1]. Since receipients of the gpiod Python bindings (in tar.gz source or .whl binary format) won't need the test C extensions (and can't run them anyway without the accompanying Python modules) the test extension code has been removed from setup.py rather than duplicated into this new file. The new build_tests.py creates a temporary directory and redirects all build-time output into it. A final step - handled by build_ext and internal to setuptools - then moves the built _ext.<python_version>-<arch>-<os>.so C extensions into tests/gpiosim and tests/procname where they can be imported. Since release packages and tests no longer share the build/ directory I have removed the "rmtree" hack from the "build_ext" override in setup.py. There should be no cases where test extensions can accidentally end up being installed into the system/user Python environment. Tested with setuptools==68.2.2 (Sep 2023), setuptools==59.8.0 (Dec 2021) and setuptools==42.0.2 (Dec 2019). [1] - https://blog.ganssle.io/articles/2021/10/setup-py-deprecated.html Phil Howard (1): bindings: python: standalone build tooling for tests bindings/python/Makefile.am | 25 +++++++---- bindings/python/build_tests.py | 79 ++++++++++++++++++++++++++++++++++ bindings/python/setup.py | 28 +----------- 3 files changed, 97 insertions(+), 35 deletions(-) create mode 100644 bindings/python/build_tests.py -- 2.34.1