Stable branch for nix

[Matt3o12]

Problem

Following the installation docs, I set up my flake to track main:

{
  inputs.kache.url = "github:kunobi-ninja/kache";

  outputs = { nixpkgs, kache, ... }: {
    # ...
    nixpkgs.overlays = [ kache.overlays.default ];
    environment.systemPackages = [ pkgs.kache ];
  };
}

However, this often causes build failures when I run nix flake update. Failing tests are not the only breakage I hit, but they are the most common. My usual workaround is to revert the flake update and retry a few days later.

error: Cannot build '/nix/store/bijwlilza9wv5hy17hv0658q1b6vc3m8-kache-0.15.0-rc.1.drv'.
       Reason: builder failed with exit code 101.
       Output paths:
         /nix/store/c4mgv1z2g7z43j2ziwwqs3wx43cw1ich-kache-0.15.0-rc.1
       Last 25 log lines:
       > test store::tests::two_removers_on_one_entry_never_double_decrement_shared_blob ... ok
       > test store::tests::test_concurrent_put_remove_never_dangles ... ok
       >
       > failures:
       >
       > ---- incremental_policy::tests::second_distinct_dynamic_miss_seeds_then_activates stdout ----
       >
       > thread 'incremental_policy::tests::second_distinct_dynamic_miss_seeds_then_activates' (8152619) panicked at src/incremental_policy.rs:968:46:
       > called `Option::unwrap()` on a `None` value
       >
       > ---- wrapper::tests::mint_session_id_is_opaque_and_distinct stdout ----
       >
       > thread 'wrapper::tests::mint_session_id_is_opaque_and_distinct' (8158431) panicked at src/wrapper.rs:7946:9:
       > assertion `left != right` failed: nanos+pid make consecutive ids distinct
       >   left: "8e20b01e7f771614"
       >  right: "8e20b01e7f771614"
       >
       >
       > failures:
       >     incremental_policy::tests::second_distinct_dynamic_miss_seeds_then_activates
       >     wrapper::tests::mint_session_id_is_opaque_and_distinct
       >
       > test result: FAILED. 1923 passed; 2 failed; 0 ignored; 0 measured; 1 filtered out; finished in 26.50s
       >
       > error: test failed, to rerun pass `-p kache --bin kache`
       For full logs, run:
         nix log /nix/store/bijwlilza9wv5hy17hv0658q1b6vc3m8-kache-0.15.0-rc.1.drv

Proposed solution

It would be great if your flake could point to a stable release (for example, a branch called stable) so that I have few updates (the whole nix build + checks always takes a very long time) and the updates always target the latest stable release, no rcs or dev versions.

Alternatives considered

I could pin to a tag, but that would mean running an outdated version of kache until I remember to bump it manually, and I rely on nix flake update to keep my system current.

Use case

Nix users who consume kache as a flake input currently have to choose between tracking main, which breaks periodically, and pinning a tag, which goes stale. A stable branch would give them a moving reference that is safe to follow automatically.