--- Makefile.orig	2016-10-03 22:11:34.000000000 +0200
+++ Makefile	2017-07-15 23:47:33.427574000 +0200
@@ -83,9 +83,9 @@ quick:
 
 unix-gcc:
 	$(MAKE) -j target=UNIX \
-		CC=gcc \
-		opt='-DSYZYGY -DTEST -DCPUS=4' \
-		CFLAGS='-Wall -Wno-array-bounds -pipe -O3 -fprofile-use \
+		CC=$(CC) \
+		opt='$(opt) -DSYZYGY -DTEST -DCPUS=4' \
+		CFLAGS='$(CFLAGS) -Wall -Wno-array-bounds -pipe -O3 -fprofile-use \
 		-mpopcnt -fprofile-correction -pthread' \
 		LDFLAGS='$(LDFLAGS) -fprofile-use -pthread -lstdc++' \
 		crafty-make