A common problem is removing old files from the installed location.

eg.
version 1 installs.
site-packages/packagename/bla.so

version 2 installs.
site-packages/packagename/_bla.so
site-packages/packagename/bla.py


However, in version 2 if we install over the top of version 1, distutils
does not remove bla.so.  Which causes the package to break because
bla.so will be used instead of bla.py
 

distutils should be able to be given a list of old files to make sure
are removed from the package.

It should work with the various installers... msi, dmg etc, as well as
when using setup.py install.

I've seen this cause breakage with numerous packages.  The solution is
to hack some old file detection into each package, or tell users 'delete
the old install first'.  Neither of which is really nice.

Specifying an old_files meta data should be able to help.

A uninstall command, based on the record of installed files, will be
proposed for #4673.

It should adress your problem, since we will be able to add a new option
in the install command.

I am leaving this issue open so we can keep track of this need.

I’m renaming this to make the status clearer: it’s about adding tests.

Jonathan Fernandes started to work on this at the last Montreal sprint.  The tests would use install_local_project, which is missing a parameter to control the destination directory (see #14270).