Forum OpenACS Development: Re: cvs woes
CVS has no "revert" mechanism per se. To back out any change you have to commit the inverse of that change. (Which, in many cases, just means yanking out the immediately previous revision and commiting that again as the latest revision).
But, in your case basically what happened is you did a vendor import of bad stuff? You did the vendor import, then after doing so, realized it was bad, broken, or corrupted in some way? In that case, I think all you need to do is retrieve the last known good vendor import, vendor import that again, and you're fine. The bad import will still be there in your CVS version history, but all its changes will have been reversed.
So say you had good vendor import A, then bad vendor import B. Just pull a clean checkout of the vendor import A out of CVS, exactly as if you were making a release tarball of that vendor code, and then import that again onto the vendor branch as vendor import C.