So for Apple to play nicely, they would have either added
/System/Library/Frameworks/Python.framework/Versions/2.3/bin to the
default $PATH, or they could have created an appropriate global
distutils config (see the guide referenced above) that put scripts in
someplace normal like /usr/local/bin/.
At any rate, it's not the place of rdiff-backup's seutp.py to look for
this issue. It should be handled at the global level by a sane Python
configuration.
Hope this helps,
Andrew
PS -- As Christopher noted, the Fink and DarwinPorts install python with
a sane configuration. The Fink system keeps everything in /sw, so it
added /sw/bin in my $PATH. It then installs python with a sys.prefix
value of /sw/. If I were creating a Linux distribution, I would
distribute python binaries with sys.prefix set to '/usr' so that scripts
would install in /usr/bin and the libraries in '/usr/lib'.