The versioning scheme used by Python (PEP 440) supports the rcN suffix
but development releases have to be named devN, not drN, which are
not supported and considered legacy versions.
Installing them might not work well when building distro packages (e.g.
with DESTDIR installs). It might be easier to install them later with a
script in the distro package.
When building from source on the local system it could still be useful to
install the packages directly, which can be enabled with separate configure
options.
The main problem with DESTDIR installations of the Python Egg is that
easy_install creates or modifies a file called easy-install.pth in the
installation directory. So it's not actually possible to simply copy
the results in DESTDIR over to the actual system as that file would have
to be merged with any existing one.
Fixes#914.
We also don't require setup.py to exist during cleanup, as e.g. with
make distcheck the source directory is not writable when the build directory
is cleaned, so setup.py can't be created (to just get removed again anyway
if VICI and the Python Eggs haven't been enabled previously).
An uninstall target is currently not supported, as there is no trivial way with
either plain setuptools or with easy_install. pip would probably be the best
choice, but we currently don't depend on it.
Tobias Brunner