> I haven't reviewed the patch in detail yet, but it seems to me that
> it fixes independent issues.

Right. First I only wanted to fix import machinery, but then I fixed a lot of "indenpendent" issues to test the patch on import. All fixes are related to surrogates. I'm splitting the big patch into small parts: see the dependency list of this issue.

I will open a new issue for the import machinery. But this patch requires extra changes which are now discussed in new issues.

> (...) why the heck does it > touch posixmodule.c?

I opened issue #8391 for this change: "os.execvpe() doesn't support surrogates in env".