From f105ab12f66a5b69f533ccf304ccfc432fcb8374 Mon Sep 17 00:00:00 2001
From: Wolfgang Walther <walther@technowledgy.de>
Date: Thu, 24 Jul 2025 10:16:17 +0200
Subject: [PATCH] workflows/build: avoid downloading from cachix

This avoids downloading results from cachix, when they don't need to be
rebuilt, which just wastes time and resources.
---
 .github/workflows/build.yml | 15 ++++++++-------
 1 file changed, 8 insertions(+), 7 deletions(-)

diff --git a/.github/workflows/build.yml b/.github/workflows/build.yml
index ff2477fec8f3..d9d0a4fb09ca 100644
--- a/.github/workflows/build.yml
+++ b/.github/workflows/build.yml
@@ -66,31 +66,33 @@ jobs:
           name: nixpkgs-ci
           authToken: "${{ secrets.CACHIX_AUTH_TOKEN }}"
 
+      - run: nix-env --install -f pinned -A nix-build-uncached
+
       - name: Build shell
         if: contains(matrix.builds, 'shell')
-        run: nix-build untrusted/ci --arg nixpkgs ./pinned -A shell
+        run: nix-build-uncached untrusted/ci --arg nixpkgs ./pinned -A shell
 
       - name: Build NixOS manual
         if: |
           contains(matrix.builds, 'manual-nixos') && !cancelled() &&
           contains(fromJSON(inputs.baseBranch).type, 'primary')
-        run: nix-build untrusted/ci --arg nixpkgs ./pinned -A manual-nixos --argstr system ${{ matrix.system }} --out-link nixos-manual
+        run: nix-build-uncached untrusted/ci --arg nixpkgs ./pinned -A manual-nixos --argstr system ${{ matrix.system }} --out-link nixos-manual
 
       - name: Build Nixpkgs manual
         if: contains(matrix.builds, 'manual-nixpkgs') && !cancelled()
-        run: nix-build untrusted/ci --arg nixpkgs ./pinned -A manual-nixpkgs -A manual-nixpkgs-tests
+        run: nix-build-uncached untrusted/ci --arg nixpkgs ./pinned -A manual-nixpkgs -A manual-nixpkgs-tests
 
       - name: Build Nixpkgs manual tests
         if: contains(matrix.builds, 'manual-nixpkgs-tests') && !cancelled()
-        run: nix-build untrusted/ci --arg nixpkgs ./pinned -A manual-nixpkgs-tests
+        run: nix-build-uncached untrusted/ci --arg nixpkgs ./pinned -A manual-nixpkgs-tests
 
       - name: Build lib tests
         if: contains(matrix.builds, 'lib-tests') && !cancelled()
-        run: nix-build untrusted/ci --arg nixpkgs ./pinned -A lib-tests
+        run: nix-build-uncached untrusted/ci --arg nixpkgs ./pinned -A lib-tests
 
       - name: Build tarball
         if: contains(matrix.builds, 'tarball') && !cancelled()
-        run: nix-build untrusted/ci --arg nixpkgs ./pinned -A tarball
+        run: nix-build-uncached untrusted/ci --arg nixpkgs ./pinned -A tarball
 
       - name: Upload NixOS manual
         if: |
@@ -100,4 +102,3 @@ jobs:
         with:
           name: nixos-manual-${{ matrix.system }}
           path: nixos-manual
-          if-no-files-found: error