I'm not sure if this is the correct component... Currently, if multiple tasks run on the same Docker worker, each task gets its own cache instance. I think this makes sense as a default behavior because it is safest. However, in some cases consumers of a cache know how to lock files and allow simultaneous access across concurrently running tasks. Mercurial store caches fall into this bucket: Mercurial obtains a lock that only allows single writers to repo stores. When triggering multiple decision tasks on try pushes, I've seen at least 4 decision tasks running on the same worker. Each worker is doing its own `hg clone` into its own independent cache. This makes the tasks much slower because 4x the amount of I/O is being performed on the worker. I'd love to be able to mark a cache as "shared" between tasks so we could make things like version control operations more efficient. Since we currently don't run multiple tasks per worker very often, this is likely a low priority.