From b273375e6c2eab100e0f8a959d4932d0a6e50cad Mon Sep 17 00:00:00 2001
From: Daniel Thwaites <danth@danth.me>
Date: Wed, 26 Feb 2025 15:49:42 +0000
Subject: [PATCH] ci: add Cachix cache (#919)

This will improve CI performance, and may also be used locally,
although this is not officially documented at this time.

I tested the required amount of space by building a `pkgs.linkFarm`
containing all testbeds, then manually pushing this to an empty Cachix
cache.

The total space used was 274 MiB of the 5 GiB free allowance, so
Cachix is good enough to cache at least 20 commits of history,
assuming the worst case scenario of every commit changing
every derivation we build.

Fixes #880
---
 .github/workflows/check.yml | 10 ++++++++++
 .github/workflows/docs.yml  |  7 +++++++
 2 files changed, 17 insertions(+)

diff --git a/.github/workflows/check.yml b/.github/workflows/check.yml
index 0859f460..dbe3e15b 100644
--- a/.github/workflows/check.yml
+++ b/.github/workflows/check.yml
@@ -18,6 +18,11 @@ jobs:
     steps:
       - uses: DeterminateSystems/nix-installer-action@v16
 
+      - uses: cachix/cachix-action@v15
+        with:
+          name: stylix
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+
       - id: get-derivations
         run: |
           set -o pipefail
@@ -84,6 +89,11 @@ jobs:
               'false'
             }}
 
+      - uses: cachix/cachix-action@v15
+        with:
+          name: stylix
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+
       - run: |
           nix build --no-update-lock-file --print-build-logs \
             github:${{
diff --git a/.github/workflows/docs.yml b/.github/workflows/docs.yml
index 98e33cc5..42ea6af5 100644
--- a/.github/workflows/docs.yml
+++ b/.github/workflows/docs.yml
@@ -25,7 +25,14 @@ jobs:
 
     steps:
       - uses: actions/checkout@v4
+
       - uses: DeterminateSystems/nix-installer-action@v16
+
+      - uses: cachix/cachix-action@v15
+        with:
+          name: stylix
+          authToken: '${{ secrets.CACHIX_AUTH_TOKEN }}'
+
       - run: nix build .#docs
 
       - uses: actions/upload-pages-artifact@v3