Using Latexmk with mpost

Question

Is it possible to tell latexmk to execute mpost paper.mp after each compilation run if paper.mp has changed?

I tried to create a custom latexmkrc rule:

add_cus_dep('mp', '1', 0, 'mpost');
sub mpost {
 system "mpost $name" ;
 popd();
 return 0;
}

But this does not seem to work

Answer 1

This seems to work:

add_cus_dep('mp', '1', 0, 'mpost');
sub mpost {
 return system("mpost $_[0].mp");
}

See answer to question on latexmk and feynmp for a more complete solution.