Accept CMake args as env vars for Python setup#3123
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davisking merged 1 commit intoNov 28, 2025
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Nice, thanks for the PR :) |
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To facilitate compiling custom Python wheels (partially addressing #3037), I updated
setup.pyto read environment variables starting withDLIB_. These variables are now automatically added to the CMake invocation as-D<VAR>=<VALUE>arguments. This allows the Python extension to be configured using the same environment variables as the native CMake build.Why this is important: modern build tools like cibuildwheel use PEP 517 standard commands (
python -m buildorpip wheel), which do not support passing custom arguments to setup.py (like--setor--no). Without this change, building dlib with specific CMake flags in CI environments requires patchingsetup.pyvia scripts (e.g., sed), which is brittle and error-prone.Environment variables now override default settings defined in
setup.py. For example,export DLIB_USE_FFMPEG=ONwill override the defaultOFFsetting. The priority order is: CLI arguments > environment variables > default options (hardcoded insetup.py).