diff '--color=auto' -ru /var/tmp/portage/sci-mathematics/mccs-1.1/work/mccs-1.1/make.local mccs-1.1/make.local
--- a/make.local	2022-04-28 08:46:08.604422769 +0200
+++ b/make.local	2022-04-28 08:47:58.444566394 +0200
@@ -107,7 +107,7 @@
 
 INC=-I$(OBJDIR) -I$(SRCDIR) -I$(SRCLIB)
 #CCCOPT=-g -Wall
-CCCOPT=-Wall -O6
+CCCOPT=-Wall $(CXXFLAGS)
 CCC=$(CXX) $(CCCOPT) $(LDFLAGS)