From fd15e1d15e1a9eba15596ab3b7f8edb39b421aa8 Mon Sep 17 00:00:00 2001
From: jappeace-sloth <sloth@jappie.me>
Date: Thu, 9 Apr 2026 08:26:37 +0000
Subject: [PATCH] Replace actions/cache with nix-community/cache-nix-action for
 nix store

actions/cache@v4 on /nix/store was placed before nix installation and
could not write to the daemon-owned store directory anyway. Replace with
nix-community/cache-nix-action@v6 which understands nix store permissions,
and move it after cachix/install-nix-action so /nix exists.

Cache key now includes npins/sources.json, nix/*.nix and *.cabal hashes
for proper invalidation.

Prompt: apply the same fix to the haskell-template-project, update your ci-nix skill as well

Co-Authored-By: Claude Opus 4.6 <noreply@anthropic.com>
---
 .github/workflows/ci.yaml | 10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index bbf1793..c1482e5 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -12,11 +12,6 @@ jobs:
     runs-on: ubuntu-latest
     steps:
     - uses: actions/checkout@v4
-    - name: Local cache
-      uses: actions/cache@v4
-      with:
-        path: /nix/store
-        key: "${{ runner.os }}-nix-cache"
     - uses: cachix/install-nix-action@v31
       with:
         nix_path: nixpkgs=channel:nixos-unstable
@@ -24,6 +19,11 @@ jobs:
           access-tokens = github.com=${{ secrets.GITHUB_TOKEN }}
           extra-substituters = https://nix-cache.jappie.me
           extra-trusted-public-keys = nix-cache.jappie.me:WjkKcvFtHih2i+n7bdsrJ3HuGboJiU2hA2CZbf9I9oc=
+    - name: Nix store cache
+      uses: nix-community/cache-nix-action@v6
+      with:
+        primary-key: nix-${{ hashFiles('npins/sources.json', 'nix/*.nix', '*.cabal') }}
+        restore-prefixes-first-match: nix-
     - run: nix-build
     - run: nix-shell --run "echo OK"
     - run: nix-shell --run "cabal build"