[Pkg-openmpi-maintainers] Bug#812991: openmpi-common: mpicc fails when both openmpi and lam are installed due to -L/usr/lib in mpicc-wrapper-data.txt

[Tomas Forsman]

Package: openmpi-common
Version: 1.6.5-9.1
Severity: important
Tags: patch

Dear Maintainer,

*** Reporter, please consider answering these questions, where appropriate ***

   * What led up to the situation?
User tried to compile openmpi program with mpicc.openmpi, while having
liblam4-dev installed at the same time.

   * What exactly did you do (or not do) that was effective (or
     ineffective)?
mpicc.openmpi -o outfile infile.c

   * What was the outcome of this action?
infile.c:(.text+0x40): undefined reference to `ompi_mpi_comm_world'
infile.c:(.text+0x51): undefined reference to `ompi_mpi_comm_world'
infile.c:(.text+0x9e): undefined reference to `ompi_mpi_comm_world'
infile.c:(.text+0xa8): undefined reference to `ompi_mpi_char'
infile.c:(.text+0xeb): undefined reference to `ompi_mpi_comm_world'
infile.c:(.text+0xf5): undefined reference to `ompi_mpi_char'

   * What outcome did you expect instead?
Silence and a linked binary.

*** End of the template - remove these template lines ***

Problem:
lrwxrwxrwx 1 root root 27 Jun 26  2015 /usr/lib/libmpi.so ->
/etc/alternatives/libmpi.so
lrwxrwxrwx 1 root root 18 Jun 26  2015 /etc/alternatives/libmpi.so ->
/usr/lib/liblam.so

mpicc.openmpi gathers compile info from /usr/share/openmpi/mpicc.openmpi-
wrapper-data.txt
which contains:
linker_flags=   -L/usr//lib
libs=-lmpi   -ldl  -lhwloc
libdir=${libdir}

'mpicc.openmpi -showme'  gives:
gcc -I/usr/lib/openmpi/include -I/usr/lib/openmpi/include/openmpi -pthread
-L/usr//lib -L/usr/lib/openmpi/lib -lmpi -ldl -lhwloc

Meaning it will pick -lmpi from /usr/lib (the LAM one) instead of
/usr/lib/openmpi/lib (the openmpi one)

Solution:
Removing '-L/usr//lib' from the linker_flags line seems to work fine.



-- System Information:
Debian Release: 8.3
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 3.16.0-4-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/bash
Init: systemd (via /run/systemd/system)

-- no debconf information