Executable h5c++ is not in the expected location

[Claudio Kozický]

I have installed libhdf5-mpi-dev (version 1.10.6+repack-5), which depends on libhdf5-openmpi-dev (version 1.10.6+repack-5). Package libhdf5-openmpi-dev currently seems to use update-alternatives to create a symlink from /usr/bin/h5pcc to the installed HDF5 C compiler wrapper at /usr/bin/h5pcc.openmpi. However the package doesn't seem to create a matching symlink for the HDF5 C++ compiler wrapper, that is it doesn't create a symlink from /usr/bin/h5c++ to /usr/bin/h5c++.openmpi. This results in a confusing scenario where the HDF5 C compiler wrapper can be invoked using command h5pcc but the HDF5 C++ compiler wrapper can only be invoked using command h5c++.openmpi. The current behaviour also breaks building HDF5 C++ programs using CMake because CMake expects the HDF5 C++ compiler wrapper to be available as h5c++. It is possible that the inability to invoke the HDF5 C++ compiler wrapper as h5c++ breaks other things that I'm unaware of.

Because I'm using Ubuntu to compile HDF5 C++ programs, I've worked around the issue by creating a similar symlink manually using command:

update-alternatives --install /usr/local/bin/h5c++ h5c++ /usr/bin/h5c++.openmpi 40

Creating the symlink using the above command has also fixed building HDF5 C++ programs using CMake. I think libhdf5-openmpi-dev should be updated to automatically symlink h5c++ just as it currently symlinks h5pcc.

I have used Ubuntu 21.10 (Impish Indri) to reproduce this issue. Please note that I have used Ubuntu via the official Docker image, but I'm sure this issue is reproducible on a proper installation as well.