01_vars/02_functions/strftime.cf fails on HPUX.
One of the conversion specifications passed to strftime(3), %F is equivalent to '%Y-%m-%d' in common libc implementations, whereas on HPUX it's something entirely different, expanding to the locale-specific full month name (i.e. March).
In ce12487, I expunged %F from the list of conversion specs for HPUX, leaving it intact for other systems, since neither this testcase, nor the companion strftime_GMT.cf are comprehensive in their testing of vonversions, I assumed incidental nature of the choices. In the discussion that ensued in https://github.com/cfengine/core/pull/1574 , it was agreed that more conversion specs must be accounted for in the acceptance tests, and that instead of sanitizing the failing testcase for HPUX only, it would be marked as broken instead, with effort redirected to fixing the internal strftime() to pet HPUX specifically.