[metapost] Metapost btex etex problem

[Akira Kakuto]

Hi,

> Is there anything I can check?

Sorry, I can't help you at present, but
try
mpost --tex=tex --debug mpsimp2
with a simpler example:

%
% mpsimp2.mp
%
beginfig(1)
  draw (0,0)--(5cm,0) withpen pencircle scaled 1pt;
  label.rt(btex $A$ etex, (5cm, 0cm));
endfig;
end.

Best,
Akira