4d3783d0d9
installer not only generates launcher scripts, it also rewrites shebangs for old-style setuptools scripts. In that case we need to write a real shebang and not just one which simple_launcher understands. Instead of patching the source interpreter path, derive the relocatable shebang from it in both places. This came up in https://github.com/msys2/MINGW-packages/issues/24738#issuecomment-3579042058