[Distutils] setuptools doesn't seem to know about lib64 on Ubuntu

[Bill Janssen]

Hi.  I'm trying to install setuptools on a Ubuntu 9.10 system (64-bit),
in a custom location:

  % python setup.py install --install-layout=deb --prefix=/opt/uplib-1.7.9
  running install
  Checking .pth file support in /opt/uplib-1.7.9/lib/python2.6/dist-packages/
  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: '/opt/uplib-1.7.9/lib/python2.6/dist-packages/test-easy-install-10270.pth'

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

      /opt/uplib-1.7.9/lib/python2.6/dist-packages/

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

  % 

The problem is that it should be looking at 

    /opt/uplib-1.7.9/lib64/python2.6/dist-packages/

which *does* exist, and *is* on the PYTHONPATH.  Is there some way I can
force this via a commandline option?

Bill