view mercurial/pure/__init__.py @ 44080:4e05272dd681

packaging: leverage os.path.relpath() in setup.py

`os.path.relpath()` has existed since Python 2.6, so we can safely use
it. This fixes a bug in the current code when the common prefix is "/"
(in which case `uplevel` would be one less than it should).

Differential Revision: https://phab.mercurial-scm.org/D7875