Fails with 3.15. Not sure why.
not ok 91 - prov.unique()
not ok 92 - epics::atomic::get(PDBProvider::num_instances) (1) == 0u (0)
ok 93 # SKIP No multilock
ok 94 # SKIP No multilock
not ok 95 - epics::atomic::get(PDBSinglePV::num_instances) (1) == 0u (0)