やはり・・・。

心配していたことが起きた。

[nori@asama]~/Desktop/work/gitage/libgitage% yum search mach
There was a problem importing one of the Python modules
required to run yum. The error leading to this problem was:

No module named cElementTree

Please install a package which provides this module, or
verify that the module is installed correctly.

It's possible that the above module doesn't match the
current version of Python, which is:
2.4.3 (#1, May 24 2008, 13:57:05)
[GCC 4.1.2 20070626 (Red Hat 4.1.2-14)]

If you cannot solve this problem yourself, please go to
the yum faq at:
http://wiki.linux.duke.edu/YumFaq

追記：
sudo rpm -U --force python-elementtree-1.2.6-5.x86_64.rpm
で上書きして出直し。
さてcのソースを探さねば。