[libc-commits] [libc] [libc] Find Python 3 in standalone (PR #118871)

[Tristan Ross via libc-commits]

RossComputerGuy wrote:

I'm running with these flags:
```
-GNinja -DCMAKE_FIND_USE_SYSTEM_PACKAGE_REGISTRY=OFF -DCMAKE_FIND_USE_PACKAGE_REGISTRY=OFF -DCMAKE_EXPORT_NO_PACKAGE_REGISTRY=ON -DCMAKE_BUILD_TYPE=Debug -DBUILD_TESTING=OFF -DCMAKE_INSTALL_LOCALEDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/share/locale -DCMAKE_INSTALL_LIBEXECDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/libexec -DCMAKE_INSTALL_LIBDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/lib -DCMAKE_INSTALL_DOCDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/share/doc/libc -DCMAKE_INSTALL_INFODIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/share/info -DCMAKE_INSTALL_MANDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/share/man -DCMAKE_INSTALL_OLDINCLUDEDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/include -DCMAKE_INSTALL_INCLUDEDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/include -DCMAKE_INSTALL_SBINDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/sbin -DCMAKE_INSTALL_BINDIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/bin -DCMAKE_INSTALL_NAME_DIR=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05/lib -DCMAKE_POLICY_DEFAULT_CMP0025=NEW -DCMAKE_FIND_FRAMEWORK=LAST -DCMAKE_STRIP=/nix/store/2r2xi5pbg29bsmqywsm5zgl8l7adky4i-gcc-wrapper-13.3.0/bin/strip -DCMAKE_RANLIB=/nix/store/2r2xi5pbg29bsmqywsm5zgl8l7adky4i-gcc-wrapper-13.3.0/bin/ranlib -DCMAKE_AR=/nix/store/2r2xi5pbg29bsmqywsm5zgl8l7adky4i-gcc-wrapper-13.3.0/bin/ar -DCMAKE_C_COMPILER=gcc -DCMAKE_CXX_COMPILER=g++ -DCMAKE_INSTALL_PREFIX=/nix/store/lfasxjrpvnnwd8imf3wfwf784mkirc3w-libc-20.0.0-unstable-2024-12-05 -DLLVM_LIBC_FULL_BUILD:BOOL=TRUE -DPython3_EXECUTABLE:STRING=/nix/store/imz4prdh762l7jvwak2s7pqpq6hy5fyy-python3-3.12.7/bin/python3.12
```

I have to specify `Python3_EXECUTABLE` since it tries executing the `yaml_to_classes.py` script in a way that makes Nix not happy.

https://github.com/llvm/llvm-project/pull/118871