Here's a status:

The problem is located in the codec that decodes the data (called by the
compile builtin).

It throws an error :

*** UnicodeDecodeError: 'charmap' codec can't decode byte 0x9d in
position 853: character maps to <undefined>

Which is caught by compile and translated into:

SyntaxError: unknown encoding: cp1252

So I see two problems:

1/ why compile throws such an error when there's an UnicodeDecodeError
2/ why compile works well under Py2 since 0x9d is not part of the 
   cp1252 mapping

I have written a test that reproduces the problem, and I am still
investigating. If I can't find the problem I will ask for help on
python-dev because I have no knowledge in the compiler internals yet.