anchor.diff:      ln -s "$out/bin/python3" "$out/bin/python"
       ln -s "$out/bin/python3-config" "$out/bin/python-config"
       ln -s "$out/lib/pkgconfig/python3.pc" "$out/lib/pkgconfig/python.pc"
  +
  +    # Determinism: rebuild all bytecode
  +    # We exclude lib2to3 because that's Python 2 code which fails
  +    # We rebuild three times, once for each optimization level
  +    find $out -name "*.py" | $out/bin/python -m compileall -q -f -x "lib2to3" -i -
  +    find $out -name "*.py" | $out/bin/python -O -m compileall -q -f -x "lib2to3" -i -
  +    find $out -name "*.py" | $out/bin/python -OO -m compileall -q -f -x "lib2to3" -i -
     '';
   
     postFixup = ''
  
positive.code:     # Python on Nix is not manylinux1 compatible. https://github.com/NixOS/nixpkgs/issues/18484
      echo "manylinux1_compatible=False" >> $out/lib/${libPrefix}/_manylinux.py
  
      # Use Python3 as default python
      ln -s "$out/bin/idle3" "$out/bin/idle"
      ln -s "$out/bin/pip3" "$out/bin/pip"
  
negative.code:        export NIX_CFLAGS_COMPILE="$NIX_CFLAGS_COMPILE -msse2"
         export MACOSX_DEPLOYMENT_TARGET=10.6
       ''}
    '';
  
    setupHook = ./setup-hook.sh;
  