From 58330fd08d58bd7f26e92c50684c0b7b137d3a5c Mon Sep 17 00:00:00 2001
From: teto <886074+teto@users.noreply.github.com>
Date: Wed, 25 Feb 2026 09:55:01 +0100
Subject: [PATCH] flake: add a devShell

that includes the formatter
---
 flake.nix                  | 17 +++++------------
 home-manager/devShell.nix  | 11 +++++++++++
 home-manager/formatter.nix | 10 ++++++++++
 3 files changed, 26 insertions(+), 12 deletions(-)
 create mode 100644 home-manager/devShell.nix
 create mode 100644 home-manager/formatter.nix

diff --git a/flake.nix b/flake.nix
index 9a2c58c3e..e4ec68cde 100644
--- a/flake.nix
+++ b/flake.nix
@@ -157,18 +157,7 @@
           lib.mapAttrs' renameTestPkg tests;
       in
       {
-        formatter = forAllPkgs (
-          pkgs:
-          pkgs.treefmt.withConfig {
-            runtimeInputs = with pkgs; [
-              nixfmt
-              deadnix
-              keep-sorted
-              nixf-diagnose
-            ];
-            settings = pkgs.lib.importTOML ./treefmt.toml;
-          }
-        );
+        formatter = forAllPkgs (pkgs: pkgs.callPackage ./home-manager/formatter.nix { });
 
         # TODO: increase buildbot testing scope
         buildbot = forCI (
@@ -214,6 +203,10 @@
           }
         );
 
+        devShells = forAllPkgs (pkgs: {
+          default = pkgs.callPackage ./home-manager/devShell.nix { };
+        });
+
         legacyPackages = forAllPkgs (
           pkgs:
           let
diff --git a/home-manager/devShell.nix b/home-manager/devShell.nix
new file mode 100644
index 000000000..4274535c3
--- /dev/null
+++ b/home-manager/devShell.nix
@@ -0,0 +1,11 @@
+{ pkgs, mkShell }:
+let
+  formatter = pkgs.callPackage ./formatter.nix { };
+in
+mkShell {
+  name = "devShell";
+  packages = [
+    pkgs.coreutils
+    formatter
+  ];
+}
diff --git a/home-manager/formatter.nix b/home-manager/formatter.nix
new file mode 100644
index 000000000..3e4c219b5
--- /dev/null
+++ b/home-manager/formatter.nix
@@ -0,0 +1,10 @@
+{ pkgs }:
+pkgs.treefmt.withConfig {
+  runtimeInputs = with pkgs; [
+    nixfmt
+    deadnix
+    keep-sorted
+    nixf-diagnose
+  ];
+  settings = pkgs.lib.importTOML ../treefmt.toml;
+}