Doesn't seem to be useful. Present since the switch to automake, so
possibly a leftover from experimentation.
config/sbr_libmh_a-config.$(OBJEXT) sbr/sbr_libmh_a-mts.$(OBJEXT): Makefile
config/sbr_libmh_a-config.$(OBJEXT) sbr/sbr_libmh_a-mts.$(OBJEXT): Makefile
-sbr_libmh_a_CPPFLAGS = ${AM_CPPFLAGS} -I./sbr \
+sbr_libmh_a_CPPFLAGS = ${AM_CPPFLAGS} \
-DNMHBINDIR='"$(bindir)"' \
-DNMHLIBEXECDIR='"$(nmhlibexecdir)"' \
-DNMHETCDIR='"@nmhetcdirinst@$(nmhetcdir)"' \
-DNMHBINDIR='"$(bindir)"' \
-DNMHLIBEXECDIR='"$(nmhlibexecdir)"' \
-DNMHETCDIR='"@nmhetcdirinst@$(nmhetcdir)"' \