Comment # 9 on bug 1094323 from Bernhard Wiedemann

While RECORD files are indeed reproducible now,
.pyc files are still not with the same type of diff as in comment 0

IMHO, there is no good reason for them to contain a random path under /tmp/
because that will not exist at runtime, so if it was used for anything,
it would be broken.
And if it is not used for anything, it does not need to be in there.

Is there already an upstream pip bug tracking that?