From 5c3bd87dd8f8f5e26f07fe55d4a671ea3b4dcfd9 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Pawe=C5=82=20Pacana?= <pawel.pacana@gmail.com>
Date: Thu, 25 Jun 2026 23:30:22 +0200
Subject: [PATCH] Restore Cachix-backed CI caching

- Use the writable mostlyobvious Cachix cache in CI instead of the GitHub Actions Nix store cache, which avoids large store snapshots.
- Keep pulling from the devenv cache and add mostlyobvious as a devenv Cachix pull cache so local and CI evaluation share substitutes.
---
 .github/workflows/main.yml | 17 +++--------------
 devenv.nix                 |  2 ++
 2 files changed, 5 insertions(+), 14 deletions(-)

diff --git a/.github/workflows/main.yml b/.github/workflows/main.yml
index 9183cd1..5d94b3a 100644
--- a/.github/workflows/main.yml
+++ b/.github/workflows/main.yml
@@ -27,23 +27,12 @@ jobs:
         with:
           extra_nix_config: |
             accept-flake-config = true
-            keep-outputs = true
-            keep-env-derivations = true
-      - name: Cache Nix store
-        uses: nix-community/cache-nix-action@v7
-        with:
-          primary-key: nix-${{ runner.os }}-${{ hashFiles('**/*.nix', 'devenv.lock', 'devenv.yaml') }}
-          restore-prefixes-first-match: nix-${{ runner.os }}-
-          gc-max-store-size-linux: 1G
-          purge: true
-          purge-prefixes: nix-${{ runner.os }}-
-          purge-created: 0
-          purge-last-accessed: P1DT12H
-          purge-primary-key: never
       - name: Set up cachix
         uses: cachix/cachix-action@v16
         with:
-          name: devenv
+          name: mostlyobvious
+          authToken: ${{ secrets.CACHIX_AUTH_TOKEN }}
+          extraPullNames: devenv
       - name: Install devenv
         run: nix profile install nixpkgs#devenv
       - name: Cache gems
diff --git a/devenv.nix b/devenv.nix
index 2d72e8e..524465c 100644
--- a/devenv.nix
+++ b/devenv.nix
@@ -5,6 +5,8 @@
 }:
 
 {
+  cachix.pull = [ "mostlyobvious" ];
+
   languages.ruby.enable = true;
   languages.ruby.version = "4.0.5";
   languages.ruby.bundler.package =
-- 
2.51.2