Function set_executable() in ccompiler.py does the following check:

    def set_executable(self, key, value):
        if isinstance(value, str):
            setattr(self, key, split_quoted(value))
        else:
            setattr(self, key, value)


The check "if isinstance(value, str)" is incorrect, because type of value can be unicode, while it should be splitted as well.