$(top_srcdir)/sntp/scm-rev: FRC.scm-rev
       $(AM_V_GEN)cd $(top_builddir)/sntp && $(MAKE) $(AM_MAKEFLAGS) check-scm-rev

PHONY: FRC.scm-rev
FRC.scm-rev:
       @: FRC.scm-rev is always out of date, triggering the check every make invocation.