problems with importing from cvs archive

All,

I'm trying to use git-cvsimport to import from a CVS archive, using:

git-cvsimport -d $CVSROOT

and am getting the following error:

	fatal: refs/heads/origin: not a valid SHA1
	fatal: master: not a valid SHA1
	warning: You appear to be on a branch yet to be born
	warning: Forcing checkout of HEAD
	fatal: just how do you expect me to merge 0 trees?
	checkout failed: 256

Is git-cvsimport meant to be universal - ie: work on any given CVS worktree - or do you need to prep the CVS worktree in any way in order for it to be used?

Or is this just a plain vanilla bug? 

Thanks,

Ed