== Using older GCC ==
Linux and Linux64 build bots are using GCC 4.5 for Try builds. But some branches will fail to build or run tests with this version of GCC because of the libstdc++ dependency it adds. Such branches are those where [https://bugzilla.mozilla.org/show_bug.cgi?id=643690 bug 643690] hasn't landed. If you want to push such a branch to Try, you need to add the following to '''mozconfig-extra-linux''' and/or '''mozconfig-extra-linuxlinux64''' in the top directory:
CC=/tools/gcc-4.3.3/installed/bin/gcc