diff -r 000000000000 -r 6474c204b198 browser/config/mozconfigs/win64/debug-nonunified
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/browser/config/mozconfigs/win64/debug-nonunified	Wed Dec 31 06:09:35 2014 +0100
@@ -0,0 +1,3 @@
+. "$topsrcdir/browser/config/mozconfigs/win64/debug"
+
+ac_add_options --disable-unified-compilation