Created attachment 8866652 [details] List of "leaks at ..." log entries Linux64-asan (with stylo enabled) found a lot of leaks in mochitests and reftests. Step to reproduce: * Add "--enable-stylo" to asan mozconfigs:  * Push try: "try: -b do -p linux64-asan -u all -t none" An example push: . I also attached the list of leaking locations, extracted from the logs.  https://hg.mozilla.org/try/rev/47bef5c8de54ee1edac4f6d924550123fe84daba  https://treeherder.mozilla.org/#/jobs?repo=try&revision=d31cf95b1ac021ba56d010754062a7f3134c7e42
Looks to me like we're leaking servo stylesheets, but not the corresponding gecko data structures.