Hi Anton - thanks for the report. https://github.com/HDFGroup/hdf5/issues/366 with the solution that "-Wl," must be prepended somehow to "-soname".
Why do you think this is not a libtool issue? Isn't it libtool's job to figure out the arguments that need to be passed? The fact that the -Wl is provided for gfortran and not for armflang makes me think even more that it is libtool. At first glance, the string "soname" does not appear in the Automake sources. But I'm not sure what changes I need to do to my configure.ac and/or Makefile.am to fix this correctly. I wish I had a workaround for you, but I just don't know the answer. Someone else here probably knows better, else I suggest posting to bug-libt...@gnu.org, ideally with a reproducible case. Happy linking, Karl