On Aug 25, 2017, at 1:06 PM, xoviat <xoviat@gmail.com> wrote:

Is pip going to fall back to building a wheel directly if any other error is raised? That's what happens with setup.py install. If so, then it may be fine if unexpected exceptions bubble up.

I doubt it. It will likely just print out the error and fail. The current “assume any error means fallback” situation is not very good, because most errors are not recoverable and what happens is we just make things slower by trying to repeat the operation which is going to fail instead of bailing as son as we know it’s going to fail.