linking fails on Linux due to unresolved symbols provided by libpthread
Linking of OPAL can fail on Linux systems if a static library has unresolved symbols provided by libpthread. On Linux the order of libraries specified on the command line is relevant.
Example: the library libopenblas uses functions provided by libpthread. In this case libpthread has to be specified after libopenblas.
To ensure that we have to add -lpthread add the end of libraries used for linking - even if another -lpthread already exists.