Just as a neat data point, we hadn't been using sccache for Firefox builds in our new CI infrastructure (Taskcluster) for various reasons. After rolling out the

Just as a neat data point, we hadn't been using sccache for Firefox builds in our new CI infrastructure (Taskcluster) for various reasons. After rolling out the sccache rewrite I fixed that, and build times in that environment dropped by 32-38%: https://treeherder.mozilla.org/perf.html#/alerts?id=4335 https://treeherder.mozilla.org/perf.html#/alerts?id=4335