Failing due to google/subpar#39 (comment)

There's a whole lot of Windows specific logic in https://github.com/bazelbuild/bazel/blob/1a0852199d05bef95fcceaa1ef244c36d393bfb0/src/main/java/com/google/devtools/build/lib/bazel/rules/python/BazelPythonSemantics.java that ends up creating the <target_name>.exe that is in this case compiler.exe.

Somewhere in there a non-UTF-8 char is being introduced, or the whole file is actually just binary and not a text-based bash file like in Unix.

I'd say I'd be better to address this issue be replacing the .par files, like we did in rules_python_external.

Agreed that the best path forward here is to upstream rules_python_external approach.