I believe that line 294 in /usr/lib/catalyst/modules/generic_stage_target.py should'nt be there as it makes the unbind(self) method raise CatalystError, even though catalyst succeeds in killing chroot process and actual unmount, the dir that failed umount in line 291.
Does this problem still exist in catalyst-2.0_rc45? The 1.x branch of catalyst is no longer supported. Where is the offending line in 2.0_rc45? What is the traceback you get?
Well, it isn't so much that it isn't supported, just that we won't be doing any coding on it. It's end of life so far as coding, but it *is* still the current "stable" version. I've honestly considered stabilizing one of the catalyst 2.0 RC's and removing catalyst 1.x just so I don't ever have to hear about it again... ;] Anyway, the solution here is to use catalyst 2.0 instead. If it is still a problem there, REOPEN this bug and we'll fix it in the 2.0 branch.