'bzr init-repo .' crashes for lack of module bz2. Help, please!

[Alan Mackenzie]

Hi, emacs!

I've just installed bazaar-2.0.3 on my Debian G/L box; I did this by
downloading the source tarball, unpacking it and running 'python
setup.py install' as root.  Before doing this, I had downloaded and
unpacked http://effbot.org/zone/element-index.htm as hinted in the file
INSTALL.

On doing 'bzr init-repo .' bzr crashes with:

  bzr: ERROR: exceptions.ImportError: failed to load 
bzrlib.repofmt.groupcompress_repo.RepositoryFormat2a: No module named bz2

, followed by a backtrace.

It seems my installation of bzr was somehow incomplete, despite
following the instructions in bzr's INSTALL.

Would somebody help me, please.

-- 
Alan Mackenzie (Nuremberg, Germany).