I tried to build mpi4py, but it fails building. Seems that it cannot find mpe library:

/usr/lib/gcc/x86_64-pc-linux-gnu/4.8.2/../../../../x86_64-pc-linux-gnu/bin/ld: cannot find -lmpe
collect2: error: ld returned 1 exit status
failure.

emerging mpe2 will eliminate the error of -lmpe, but then there is a similar error with -llmpe.

I will attach build log.