$OpenBSD: patch-tasks_toolchains_gcc_rake,v 1.2 2017/11/01 21:44:44 jeremy Exp $
Index: tasks/toolchains/gcc.rake
--- tasks/toolchains/gcc.rake.orig
+++ tasks/toolchains/gcc.rake
@@ -1,7 +1,7 @@
 MRuby::Toolchain.new(:gcc) do |conf, _params|
   [conf.cc, conf.objc, conf.asm].each do |cc|
     cc.command = ENV['CC'] || 'gcc'
-    cc.flags = [ENV['CFLAGS'] || %w(-g -std=gnu99 -O3 -Wall -Werror-implicit-function-declaration -Wdeclaration-after-statement -Wwrite-strings)]
+    cc.flags = [ENV['CFLAGS'] || '-g -O3'] + %w(-std=gnu99 -Wall -Werror-implicit-function-declaration -Wdeclaration-after-statement -Wwrite-strings)
     cc.defines = %w(DISABLE_GEMS)
     cc.option_include_path = '-I%s'
     cc.option_define = '-D%s'
