FreeBSD 4.1 bootstrapping aid (``:C'' make(1) modifier used

by gnu/usr.bin/binutils/as/Makefile.inc0 is not there).

XXX: make(1) should return with a non-zero exit status here.

Makefile

@@ -148,6 +148,11 @@ upgrade_checks:
 		if ! make -m ${.CURDIR}/share/mk test > /dev/null 2>&1; then \
 			make make; \
 		fi
+	@cd ${.CURDIR}; \
+		if make -V .CURDIR:C/.// 2>&1 >/dev/null | \
+		    grep -q "Unknown modifier 'C'"; then \
+			make make; \
+		fi
 
 #
 # A simple test target used as part of the test to see if make supports