I just tried mtree with the distributed BSD.root.dist etc.. files.
It seems that the specification has changed.
Anyway it gives these messages:
    mtree: unknown keyword owner
    mtree: failed at line 9 of the specification

and indeed the keylist in src/usr.sbin/mtree/misc.c doesn't contain this 
keyword, but contains uname.
The manpage mentions owner ..

Where's the error ?
Is mtree under reconstruction ?

regards
kim

------------------------------------------------------------------------------