OpenMPI libraries are incompatible with --as-needed in gcc's link command

[Dmitry Mikushin]

In Ubuntu 11.10 an application that links against libmpi_f77 of OpenMPI 1.5.4 or 1.4.3 built from source *FAILS* to link due to unresolvable relocations:

program main
include 'mpif.h'
integer ierr
call mpi_init(ierr)
end

marcusmae@loveland:~/Programming/mpitest$ mpif90 -g mpitest.f90
/usr/bin/ld: /tmp/cc3NLduM.o(.debug_info+0x542): unresolvable
R_X86_64_64 relocation against symbol `mpi_fortran_argv_null_'
/usr/bin/ld: /tmp/cc3NLduM.o(.debug_info+0x55c): unresolvable
R_X86_64_64 relocation against symbol `mpi_fortran_argv_null_'
/usr/bin/ld: /tmp/cc3NLduM.o(.debug_info+0x5d2): unresolvable
R_X86_64_64 relocation against symbol `mpi_fortran_errcodes_ignore_'
/usr/bin/ld: /tmp/cc3NLduM.o(.debug_info+0x5ec): unresolvable
R_X86_64_64 relocation against symbol `mpi_fortran_errcodes_ignore_'

The solution is to remove --as-needed from the linker command line in gcc specs.

This issue is also described in http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=608901

[Matthias Klose (doko)]

looks like an issue with ld.bfd. you can work around it by using gold for now.

  mpif90 -B/usr/lib/gold-ld -g mpitest.f90