From dedd9a6b6d6c6b19a00022318cb6dde0fc82e1bb Mon Sep 17 00:00:00 2001
From: Ievgen Pyrogov <iamexile@gmail.com>
Date: Tue, 14 Jul 2026 17:25:32 +0200
Subject: [PATCH] Speed up Nix-based CI

---
 .github/workflows/ci.yml      | 34 ++++++++++++++++++++++------------
 .github/workflows/release.yml |  8 +++++---
 flake.nix                     | 11 +++++++++++
 3 files changed, 38 insertions(+), 15 deletions(-)

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
index 6c08395..d6e3930 100644
--- a/.github/workflows/ci.yml
+++ b/.github/workflows/ci.yml
@@ -10,6 +10,10 @@ on:
 permissions:
   contents: read
 
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
 jobs:
   test:
     name: Test
@@ -25,47 +29,53 @@ jobs:
         with:
           path: deps
           key: ${{ runner.os }}-mix-deps-${{ hashFiles('mix.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-mix-deps-
 
       - name: Restore build cache
         uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25 # v5
         with:
           path: _build
-          key: ${{ runner.os }}-mix-build-${{ hashFiles('flake.lock', 'mix.lock') }}
+          key: ${{ runner.os }}-mix-build-${{ hashFiles('flake.nix', 'flake.lock') }}-${{ hashFiles('mix.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-mix-build-${{ hashFiles('flake.nix', 'flake.lock') }}-
 
       - name: Restore PLT cache
         uses: actions/cache@caa296126883cff596d87d8935842f9db880ef25 # v5
         with:
           path: priv/plts
-          key: ${{ runner.os }}-plt-${{ hashFiles('flake.lock', 'mix.lock') }}
+          key: ${{ runner.os }}-plt-${{ hashFiles('flake.nix', 'flake.lock') }}-${{ hashFiles('mix.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-plt-${{ hashFiles('flake.nix', 'flake.lock') }}-
 
       - name: Install dependencies
-        run: nix develop --command mix deps.get --check-locked
+        run: nix develop .#ci --command mix deps.get --check-locked
 
       - name: Compile
-        run: nix develop --command mix compile --warnings-as-errors
+        run: nix develop .#ci --command mix compile --warnings-as-errors
 
       - name: Check formatting
-        run: nix develop --command mix format --check-formatted
+        run: nix develop .#ci --command mix format --check-formatted
 
       - name: Check unused dependencies
-        run: nix develop --command mix deps.unlock --check-unused
+        run: nix develop .#ci --command mix deps.unlock --check-unused
 
       - name: Check dependency cycles
-        run: nix develop --command mix xref graph --format cycles --fail-above 0
+        run: nix develop .#ci --command mix xref graph --format cycles --fail-above 0
 
       - name: Run unit tests without soffice
-        run: nix develop --command mix test --exclude integration
+        run: nix develop .#ci --command mix test --exclude integration
         env:
           URP_INTEGRATION: "0"
 
       - name: Build documentation
-        run: nix develop --command mix docs --warnings-as-errors
+        run: nix develop .#ci --command mix docs --warnings-as-errors
 
       - name: Audit Hex dependencies
-        run: nix develop --command mix hex.audit
+        run: nix develop .#ci --command mix hex.audit
 
       - name: Run dialyzer
-        run: nix develop --command mix dialyzer
+        run: nix develop .#ci --command mix dialyzer
 
       - uses: docker/setup-buildx-action@bb05f3f5519dd87d3ba754cc423b652a5edd6d2c # v4
 
@@ -88,6 +98,6 @@ jobs:
           timeout 30 bash -c 'until nc -z localhost 2002; do sleep 1; done'
 
       - name: Run integration tests
-        run: nix develop --command mix test --include integration --include lo26
+        run: nix develop .#ci --command mix test --include integration --include lo26
         env:
           URP_INTEGRATION: "1"
diff --git a/.github/workflows/release.yml b/.github/workflows/release.yml
index 3b59298..617c7d8 100644
--- a/.github/workflows/release.yml
+++ b/.github/workflows/release.yml
@@ -30,19 +30,21 @@ jobs:
         with:
           path: deps
           key: ${{ runner.os }}-mix-deps-${{ hashFiles('mix.lock') }}
+          restore-keys: |
+            ${{ runner.os }}-mix-deps-
 
       - name: Install dependencies
-        run: nix develop --command mix deps.get --check-locked
+        run: nix develop .#ci --command mix deps.get --check-locked
 
       - name: Verify tag, package version, and changelog
         run: |
           version="$(tr -d '[:space:]' < VERSION)"
           test "${GITHUB_REF_NAME}" = "v${version}"
           grep --fixed-strings --quiet "## [v${version}]" CHANGELOG.md
-          nix develop --command mix hex.build
+          nix develop .#ci --command mix hex.build
 
       - name: Publish to Hex
-        run: nix develop --command mix hex.publish --yes
+        run: nix develop .#ci --command mix hex.publish --yes
         env:
           HEX_API_KEY: ${{ secrets.HEX_API_KEY }}
 
diff --git a/flake.nix b/flake.nix
index ca1fa85..92c64b9 100644
--- a/flake.nix
+++ b/flake.nix
@@ -12,6 +12,8 @@
         let
           pkgs = nixpkgs.legacyPackages.${system};
           beamPackages = pkgs.beam.packages.erlang_29;
+          # CI/release tasks are headless; avoid the full wx and systemd closure.
+          ciBeamPackages = pkgs.beamMinimal29Packages;
         in
         {
           default = pkgs.mkShell {
@@ -24,6 +26,15 @@
               pkgs.uv
             ];
           };
+
+          ci = pkgs.mkShell {
+            packages = [
+              ciBeamPackages.erlang
+              ciBeamPackages.elixir_1_20
+              ciBeamPackages.hex
+              ciBeamPackages.rebar3
+            ];
+          };
         }
       );
     };