[metapost] makempx

[John Kitzmiller]

Happy new year, but a sad old problem keeps raising it's head for me
when using btex...etex:

 
This is MetaPost, version 1.102 (kpathsea version 3.5.7)
(./fig.mpsh: makempx: not found

>> fig.mp
>> fig.mpx
! Unable to make mpx file.
l.15 label.llft(btex $A$ etex, (-20,-10));


The bash error 'sh: makempx: not found' is a clue, but, my impression
was that btex ... etex label conversions would be handled by mpost 1.x
(MPlib) instead of calling external programs. What might I be
doing/looking at wrong? (again)

Thanks,

John