From 06e75e55e3caf312aeb2ca3a185c6c0499b16db7 Mon Sep 17 00:00:00 2001
From: Sridhar Ratnakumar <3998+srid@users.noreply.github.com>
Date: Sun, 9 Apr 2023 09:51:56 -0400
Subject: [PATCH] Parametrize `systems` using `github:nix-systems` (#97)

---
 .github/workflows/ci.yaml | 10 ++--------
 Jenkinsfile               |  9 ++-------
 flake.lock                | 16 ++++++++++++++++
 flake.nix                 |  3 ++-
 4 files changed, 22 insertions(+), 16 deletions(-)

diff --git a/.github/workflows/ci.yaml b/.github/workflows/ci.yaml
index c25917a..422b275 100644
--- a/.github/workflows/ci.yaml
+++ b/.github/workflows/ci.yaml
@@ -24,15 +24,9 @@ jobs:
           nix build -j auto -L
       - name: Flake checks 🧪
         run: |
-          # Because 'nix flake check' is not system-aware
-          # See https://srid.ca/haskell-template/checks
-          nix run nixpkgs#sd \
-            'systems = nixpkgs.lib.systems.flakeExposed' \
-            'systems = [ "x86_64-linux" ]' \
-            flake.nix
-
           # Sandbox must be disabed for:
           # https://github.com/srid/haskell-flake/issues/21
           nix \
             --option sandbox false \
-            flake check -L
+            flake check -L \
+            --override-input systems github:nix-systems/x86_64-linux
diff --git a/Jenkinsfile b/Jenkinsfile
index 18a64e6..b53c34c 100644
--- a/Jenkinsfile
+++ b/Jenkinsfile
@@ -14,17 +14,12 @@ pipeline {
         stage ('Flake checks') {
             steps {
                 sh '''
-                    # Because 'nix flake check' is not system-aware
-                    # See https://srid.ca/haskell-template/checks
-                    nix run nixpkgs#sd \
-                        'systems = nixpkgs.lib.systems.flakeExposed' \
-                        'systems = [ "x86_64-linux" ]' \
-                        flake.nix
                     # Sandbox must be disabed for:
                     # https://github.com/srid/haskell-flake/issues/21
                     nix \
                         --option sandbox false \
-                        flake check -L                    
+                        flake check -L \
+                        --override-input systems github:nix-systems/x86_64-linux
                    '''
             }
         }
diff --git a/flake.lock b/flake.lock
index d0d2905..8e37510 100644
--- a/flake.lock
+++ b/flake.lock
@@ -104,9 +104,25 @@
         "haskell-flake": "haskell-flake",
         "mission-control": "mission-control",
         "nixpkgs": "nixpkgs",
+        "systems": "systems",
         "treefmt-nix": "treefmt-nix"
       }
     },
+    "systems": {
+      "locked": {
+        "lastModified": 1681028828,
+        "narHash": "sha256-Vy1rq5AaRuLzOxct8nz4T6wlgyUR7zLU309k9mBC768=",
+        "owner": "nix-systems",
+        "repo": "default",
+        "rev": "da67096a3b9bf56a91d16901293e51ba5b49a27e",
+        "type": "github"
+      },
+      "original": {
+        "owner": "nix-systems",
+        "repo": "default",
+        "type": "github"
+      }
+    },
     "treefmt-nix": {
       "inputs": {
         "nixpkgs": [
diff --git a/flake.nix b/flake.nix
index 4ecd6e0..456b61c 100644
--- a/flake.nix
+++ b/flake.nix
@@ -2,6 +2,7 @@
   description = "srid/haskell-template: Nix template for Haskell projects";
   inputs = {
     nixpkgs.url = "github:nixos/nixpkgs/nixpkgs-unstable";
+    systems.url = "github:nix-systems/default";
     flake-parts.url = "github:hercules-ci/flake-parts";
     haskell-flake.url = "github:srid/haskell-flake";
     treefmt-nix.url = "github:numtide/treefmt-nix";
@@ -12,7 +13,7 @@
 
   outputs = inputs@{ self, nixpkgs, flake-parts, ... }:
     flake-parts.lib.mkFlake { inherit inputs; } {
-      systems = nixpkgs.lib.systems.flakeExposed;
+      systems = import inputs.systems;
       imports = [
         inputs.haskell-flake.flakeModule
         inputs.treefmt-nix.flakeModule