The pkgconfig files contain wrong names for the shared libraries (they are
prefixed with `lib`).

grep "Libs" /usr/lib/hpc/gnu8/openmpi3/hdf5/1.10.4/lib64/pkgconfig/hdf5.pc
Libs: -L${libdir} -llibhdf5

The libraries therefore cannot be found, e.g.:

ml gnu hdf5

g++ $(pkg-config --libs hdf5)
/usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld: cannot
find -llibhdf5
collect2: error: ld returned 1 exit status

g++ -lhdf5
/usr/lib64/gcc/x86_64-suse-linux/8/../../../../x86_64-suse-linux/bin/ld:
/usr/lib64/gcc/x86_64-suse-linux/8/../../../../lib64/crt1.o: in function
`_start':
/home/abuild/rpmbuild/BUILD/glibc-2.29/csu/../sysdeps/x86_64/start.S:104:
undefined reference to `main'
collect2: error: ld returned 1 exit status

Cheers