The top-level mozconfig for B2G builds (for devices or emulators, not B2G Desktop) is default-gecko-config in the gonk-misc project; it includes Gecko's b2g/config/mozconfigs/common (which includes build/mozconfig.common), but not b2g/config/mozconfigs/common.override (-> build/mozconfig.common.override). This means that a Try run which adds non-default config flags to build/mozconfig.common.override in order to test them will silently fail to affect B2G builds. As a demonstration, this Try run adds `exit 1` to mozconfig.common.override, which should break all builds but doesn't affect B2G: https://treeherder.mozilla.org/#/jobs?repo=try&revision=fa22b3f35e11
Created attachment 8631947 [details] [review] Add b2g/config/mozconfigs/common.override to default-gecko-config
Can you merge it?
A better link for the merge - https://github.com/mozilla-b2g/gonk-misc/commit/c490ae41c67f892232599f4ef049467a922b613e