$ pkg-config --list-all [lots of output, then] Variable 'exec_prefix' not defined in '/usr/lib/pkgconfig/mpich2-ch3.pc' $ cat /usr/lib/pkgconfig/mpich2-ch3.pc # this gives access to the mpich2 header files Name: mpich2 Description: MPICH2 is an implementation of the Message-Passing Interface (MPI). The goals of MPICH2 are to provide an MPI implementation for important platforms, including clusters, SMPs, and massively parallel processors. It also provides a vehicle for MPI implementation research and for developing new and better parallel programming environments. Version: 1.0.8 Requires: Libs: -L${exec_prefix}/lib -lmpich -lmpichcxx -lpthread Cflags: -march=i686 -O2 -pipe -O2 -I${prefix}/include -DMPICH_IGNORE_CXX_SEEK I compared with some other .pc and they all seem to define their vars: $ cat /usr/lib/pkgconfig/xorg-evdev.pc sdkdir=/usr/include/xorg Name: xorg-evdev Description: X.Org evdev input driver. Version: 2.1.2 Cflags: -I${sdkdir} I didn't see anything in the mpich2 ebuild about this, so maybe its an upstream issue? The science overlay mpich2 ebuild also exhibits the same issue. I found this because the miro (bug #131527) runs "pkg-config --list-all" and then dies with the above error.
Mpich2 pkgconfig file is fixed in both the overlay and cvs.