When I landed bug 676252, I got failures on OSX and Windows builds because they were getting an empty string for OBJ_SUFFIX. The only reason I can think of to explain that is if autoconf.mk was not refreshed. In fact, the backout of bug 676252 failed on platforms where the bug 676252 landing worked because of that: autoconf.mk was still containing the $(error) value, while config/config.mk was not resetting it anymore, leading to an error.
There is a rule in client.mk to refresh autoconf.mk, but nothing depends on it. Also, nothing takes care of js/src/config/autoconf.mk. I think autoconf.mk should be refreshed, like Makefiles, from rules.mk.
Created attachment 556486 [details] [diff] [review] Refresh autoconf.mk when autoconf.mk.in is modified
Comment on attachment 556486 [details] [diff] [review] Refresh autoconf.mk when autoconf.mk.in is modified This scares me a little bit, but ok. r=me