Releasing from Mercurial repo -- procedures?

[Benson Margulies]

> Not the tagging: You create a named branch, make all the changes you
> need to do, cut the beta release from that.  *Then* you merge your
> branch back into the mainline, and *then* tag on the mainline.  (If you
> tag in the branch, the tag won't be visible on the mainline.)
> 

This procedure seems to violate a configuration management
truth-in-labelling; you aren't putting the label on the exact source
code you built from.