The diffseq module seems to require MIN and MAX to be defined, so add a dependency on the minmax module to diffseq:
--- a/modules/diffseq 2008-02-02 20:15:52.854807273 -0500 +++ b/modules/diffseq 2008-02-02 20:17:29.378777027 -0500 @@ -5,6 +5,7 @@ lib/diffseq.h Depends-on: +minmax configure.ac: