This is a heads up that once bug 1558598 (on autoland now) sticks it will change how to run test suites with WebRender enabled to make things simpler and more consistent.
Previously, if you ran tests with `./mach <whatever>` WebRender may or may not have been enabled depending on the hardware being used. To force it on or off you'd have to either set the preference (e.g. gfx.webrender.all=true) or set environment variables (e.g. MOZ_WEBRENDER=1). With bug 1558598, this is no longer the case. Now, WebRender is disabled unless the test is explicitly run with `--enable-webrender`, regardless of underlying hardware. So e.g. if you run `MOZ_WEBRENDER=1 ./mach reftest foo` this will run with WebRender disabled, because you didn't pass `--enable-webrender` to `./mach reftest` and it will override your `MOZ_WEBRENDER=1` and disable WebRender anyway. The same goes for the pref. All the test harnesses I could find (junit, gtest, mochitest, reftest, WPT, raptor, talos, cppunit, xpcshell, marionette, marionette derivatives, and jit) now support the `--enable-webrender` flag and expose them via their corresponding mach commands. Mozharness scripts used to run these tests have also been updated so tests running in taskcluster automation are similarly consistent. This also works when running tests on both desktop and Android (WR is supported only on GeckoView-based things, not Fennec). There used to be a `--disable-webrender` flag on some harnesses, which has been removed as redundant; simply omitting `--enable-webrender` will forcibly disable WebRender. Also, mozinfo (the thing used to evaluate the webrender condition in mochitest.ini/xpcshell.ini annotations and WPT meta files) is also now keying off the presence of the `--enable-webrender` flag and so should behave consistently with local test runs. Previously it was possible to be running tests with WR enabled in a way that mozinfo would think it was disabled, which should no longer be the case. Please let me know if you run into any issues or have questions. Cheers, kats _______________________________________________ dev-platform mailing list dev-platform@lists.mozilla.org https://lists.mozilla.org/listinfo/dev-platform