On Tue, Nov 16, 2021 at 01:00:21PM +0100, Ævar Arnfjörð Bjarmason wrote:

+### Remove GNU make implicit rules
+
+## This speeds things up since we don't need to look for and stat() a
+## "foo.c,v" every time a rule referring to "foo.c" is in play. See
+## "make -p -f/dev/null | grep ^%::'".
+%:: %,v
+%:: RCS/%,v
+%:: RCS/%
+%:: s.%
+%:: SCCS/s.%

`MAKEFLAGS += -r` should have the same effect (and more)