Why not to stop upgradepkg from double-installing the package
since I was thinking about patching it out for speed on armedslack:

19:06 < volkerdi> Imagine symlinks turning into directories and vice-versa
19:07 < volkerdi> If you patch it out, you'll realize the issue within a year or so.
19:10 < volkerdi> A good example is when the /usr/lib/zoneinfo dir moved to
                  /usr/share/zoneinfo.  There was a link from /usr/share/zoneinfo to
                  /usr/lib/zoneinfo, and in an upgrade the locations of the dir and
                  link swapped.  Pass one (ip), package is extracted through the old
                  link to the old dir.  Pass two (rp), rm -rf is applied to the old
                  link.  At this point there's no zoneinfo database.  Pass three
                  (ip), fixes that problem.