Bug#579307: mpi-default-bin: Incomplete alternatives system?

[Torquil Macdonald Sørensen]

Package: mpi-default-bin
Version: 0.6
Severity: normal

Hi! After installing 'mpi-default-bin', i get the following message:

update-alternatives: using /usr/bin/mpirun.openmpi to provide /usr/bin/mpirun (mpirun) in auto mode.

which is fine. However, it seems that openmpi-bin also adjusts the mpiexec-symlink:

root at asus:/home/tmac# ls -l /etc/alternatives/mpiexec
lrwxrwxrwx 1 root root 24 Apr 26 22:49 /etc/alternatives/mpiexec -> /usr/bin/mpiexec.openmpi

Before installation of 'mpi-default-bin', this pointed to a
mpich2 mpiexec.

The mystery is: mpiexec doesn't seem to be a valid alternatives "keyword":

root at asus:/home/tmac# update-alternatives --display mpiexec
update-alternatives: error: no alternatives for mpiexec.

At the same time:

root at asus:/home/tmac# ls -l /usr/bin/mpiexec*
lrwxrwxrwx 1 root root     25 Apr 26 22:49 /usr/bin/mpiexec -> /etc/alternatives/mpiexec
-rwxr-xr-x 1 root root  50184 Apr 20 10:44 /usr/bin/mpiexec.gforker
-rwxr-xr-x 1 root root 135472 Apr 20 10:44 /usr/bin/mpiexec.hydra
lrwxrwxrwx 1 root root     26 Apr 21 02:27 /usr/bin/mpiexec.mpich2 -> ../share/mpich2/mpiexec.py
lrwxrwxrwx 1 root root      7 Apr 26 22:49 /usr/bin/mpiexec.openmpi -> orterun


Bottom line: I don't understand how mpi-default-bin can modify my
/etc/alternatives/mpiexec symlink, while at the same time 'mpiexec'
is not a valid alternatives symlink, as displayed by the failure
of the 'update-alternatives' command above?

Btw, is there a way to see a valid list of alternatives keywords?
It is apparently not enough to look at the symlinks in
/etc/alternatives, since some of them will not be accessible through
the update-alternatives command.

Thanks!
Torquil Sørensen

-- System Information:
Debian Release: squeeze/sid
  APT prefers unstable
  APT policy: (500, 'unstable')
Architecture: amd64 (x86_64)

Kernel: Linux 2.6.32-3-amd64 (SMP w/2 CPU cores)
Locale: LANG=en_GB.UTF-8, LC_CTYPE=en_GB.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash

Versions of packages mpi-default-bin depends on:
ii  openmpi-bin                   1.4.1-3    high performance message passing l

mpi-default-bin recommends no packages.

mpi-default-bin suggests no packages.

-- no debconf information