Hi, On 2026-07-17 08:27:39 -0700, Jacob Champion wrote: > On Fri, Jul 17, 2026 at 6:06 AM Andres Freund <[email protected]> wrote: > > That's how it works. We restore the cache for master and for the current > > branch. We save the cache, after pruning it, for the current branch iff the > > hit rate was < 80%. > > > > It'd be nice if we could restore the cache for the "base branch" of a > > branch, > > instead of master, but that's not currently possible in GHA, from what I can > > tell. Only caches on the default branch are accessible to other branches. > > Quick tangent: is there a reason we put the refname into the cache > key? It seems like some of the logic there would happen by default if > we used the same cache prefix for all branches, since I thought GitHub > would perform the fallback-to-default-branch for us.
For cfbot it's kinda important to have *both* the master and branch specific caches for a run. Often, after a rebase of a branch to a newer master, the branch specific key will have a lower hit rate than during the last run, but master's cache applies to a lot of the part of the build not modified by the branch. I also have some hope that eventually github will allow using caches from more than just the default branch. For testing to-be-backpatched bug fixes - on fix specific, per-major branches, it's pretty painful that they can only start with master's cache. Greetings, Andres Freund
