logilab-devtools #8464 new standard setup.py breaks if setuptools is installed [rejected]

When using the new standard setup.py, if the python-setuptools package is installed, everything breaks when trying to build the debian package without using lgp build. This will be a big problem on Debian's autobuilder because the build-dependencies are not necessarily uninstalled after a package is built, and therefore, python-setuptools might be installed on an autobuilder (same thing for users wanting to rebuild a package from source).

Sample error:

$ fakeroot debian/rules binary
# python module build
python setup.py -q build
package init file './__init__.py' not found (or not a regular file)
package init file './tests/__init__.py' not found (or not a regular file)
touch build-stamp
       rm -f debian/uhs-system-upgrade.substvars
       rm -f debian/uhs-system-upgrade.*.debhelper
       rm -f debian/uhs-system-upgrade.debhelper.log
       rm -rf debian/uhs-system-upgrade/
       rm -f debian/files
       find .  \( \( -type f -a \
               \( -name '#*#' -o -name '.*~' -o -name '*~' -o -name DEADJOE \
                -o -name '*.orig' -o -name '*.rej' -o -name '*.bak' \
                -o -name '.*.orig' -o -name .*.rej -o -name '.SUMS' \
                -o -name TAGS -o \( -path '*/.deps/*' -a -name '*.P' \) \
               \) -exec rm -f {} \; \) -o \
               \( -type d -a -name autom4te.cache -prune -exec rm -rf {} \; \) \)
       rm -f *-stamp
       install -d debian/uhs-system-upgrade
python setup.py -q install --no-compile --prefix=debian/uhs-system-upgrade/usr/
error: can't create or remove files in install directory

The following error occurred while trying to add or remove files in the
installation directory:

   [Errno 2] No such file or directory: 'debian/uhs-system-upgrade/usr//lib/python2.5/site-packages/test-easy-install-9882.pth'

The installation directory you specified (via --install-dir, --prefix, or
the distutils default setting) was:


This directory does not currently exist.  Please create it and try again, or
choose a different installation directory (using the -d or --install-dir

make: *** [install] Erreur 1
done in<not specified>
load left0.000
closed by<not specified>