[metapost] mpost does not work]

[Karl Berry]

Akira reminds me that we already noticed this issue before the release,
and the answer is that you have to include --engine, as in:

 kpsewhich --all --engine=metapost mpost.mem

I could have kpsewhich do that by default with .mem files, I guess.  And
for .base.  Not for .fmt, though.  Probably should say something in the
--help message.  I did write about in the manual
(http://tug.org/texinfohtml/kpathsea.html#Path-searching-options), but
managed to forget that already, sigh.

Best,
Karl