[metapost] metapost and groff

[Nicola]

In article <201110280300.p9S30PPk001338 at tahoe.cs.dartmouth.edu>,
 Doug McIlroy <doug at cs.dartmouth.edu> wrote:

> I apologize for misspelling the URL.  It is
> tug.org/tutorials/mp/grdemo-doc.pdf
> 
> The labels are not Latex or Tex; they are for the old-testament
> universe--eqn, troff, groff.  Option -T in this mpost (0.993)
> promises, and demonstrably tries, to handle them.

On a related note, I have tried to used troff/groff with mpost 1.504 without 
success. The following

mpost -troff -debug fig.mp

results in

This is MetaPost, version 1.504 (kpathsea version 6.0.1)
(mpost.mp (/usr/local/texlive/2011/texmf-dist/metapost/base/plain.mp
Preloading the plain mem file, version 1.004)) (./fig.mpmakempx debug: ./fig.mp: 
running command soelim
makempx debug: ./fig.mp: running command eqn -Tps -d$$
makempx debug: ./fig.mp: running command troff -Tps
fatal: Cannot find DESCmakempx fatal: ./fig.mp: Cannot find DESC

>> fig.mp
>> fig.mpx
! Unable to make mpx file.

I wonder whether this is a bug.

Nicola