-depend: Makefile
-Makefile: FORCE
- @( sed -e '/^# DO NOT DELETE THIS LINE.*/,$$d' < Makefile; \
- echo '# DO NOT DELETE THIS LINE -- make depend depends on it.'; \
- echo; \
+#
+# We check if any depfile is newer than Makefile and decide to
+# concatenate only if that is true, or if 'test' (a.k.a [ )
+# doesn't have the option to figure it out (-nt).
+#
+# To check if test has the file age comparison operator, we
+# simply try, and rely test to exit with 0 if the comparison
+# was true, 1 if false, and most importantly, 2 if it doesn't
+# recognise the operator.
+depend:
+ @catdepends=false; \
+ if [ Makefile -nt Makefile ] 2>/dev/null || [ $$? = 1 ]; then \