Cache not saved when matrix is used

[ypsvlq]

After switching my workflow file to define its different targets in a matrix, only the first worker to complete saves its cache. It seems like they are all given the same key?

Example (wasm build saves, others don't).

[leninmehedy]

We seem to have hit similar issue with caching

Failed to save: Unable to reserve cache with key setup-zig-tarball-zig-linux-x86_64-0.13.0, another job may be creating this cache. More details: Cache already exists. Scope: refs/pull/111/merge, Key: setup-zig-tarball-zig-linux-x86_64-0.13.0, Version: f8c830ea35e811240be9d5006cf70b8d772b24706f3caffa189d7df216131715
fetch took 186402 m