Problem also observed run slocal is run by exmh.  When run
from another program mail just isn't file anywhere and just
disappears.  Nothing in .maildelivery matches.  And yes I
have .maildelivery security set up correctly.

Downloading the source package and recompiling it without
either of the two addon patches made it suddenly start
working again.

I'm going to see if problem still occurs on latest version
of nmh-1.0, if it does that I'll try to work up a patch for
it.