<hr><i>drh added on 2009-11-12 16:41:55:</i><br>
Because Fossil is distributed, it has no way of knowing whether or not the
tag exists.  It can check its local repository, certainly.  But you don't
necessarily want to fail the cancel in that case because the tag might exist
in some other repository that you just have not synced with yet.

I will convert this to a "feature request" to issue a warning if the tag
does not exist in the local repository.