From 281ffa987c258b62de853178b382da1eaa9abd61 Mon Sep 17 00:00:00 2001
From: Matt Sturgeon <matt@sturgeon.me.uk>
Date: Sat, 30 May 2026 23:44:21 +0100
Subject: [PATCH] nixfmt: add versionCheckHook

Replace the `passthru.tests` --version test by running versionCheckHook
during the package build.

As `haskellPackages.mkDerivation` is very locked-down and doesn't allow
access to things like `nativeInstallCheckInputs` (or any input lists),
we add a separate `.overrideAttrs` call to the pipeline.

    Running phase: installCheckPhase
    Executing versionCheckPhase
    Successfully managed to find version 1.3.0 in the output of the command /nix/store/3fg7y7qww3c3hvyb66n75d9j5y362n4j-nixfmt-1.3.0/bin/nixfmt --version
    nixfmt 1.3.0
    Finished versionCheckPhase

(cherry picked from commit ce5210e9c728c8a89a103d7a6c8c6662cac081c3)
---
 pkgs/by-name/ni/nixfmt/package.nix | 28 ++++++++++++++++------------
 1 file changed, 16 insertions(+), 12 deletions(-)

diff --git a/pkgs/by-name/ni/nixfmt/package.nix b/pkgs/by-name/ni/nixfmt/package.nix
index 93a198f73f2a..ebd16230063c 100644
--- a/pkgs/by-name/ni/nixfmt/package.nix
+++ b/pkgs/by-name/ni/nixfmt/package.nix
@@ -2,27 +2,31 @@
   haskell,
   haskellPackages,
   lib,
-  runCommand,
-  nixfmt,
+  stdenv,
+  versionCheckHook,
 }:
 let
   inherit (haskell.lib.compose) overrideCabal justStaticExecutables;
 
-  overrides = {
+  cabalOverrides = {
     passthru.updateScript = ./update.sh;
-
     teams = [ lib.teams.formatter ];
-
-    # These tests can be run with the following command.
-    #
-    # $ nix-build -A nixfmt.tests
-    passthru.tests = runCommand "nixfmt-tests" { nativeBuildInputs = [ nixfmt ]; } ''
-      nixfmt --version > $out
-    '';
   };
+
+  # haskellPackages.mkDerivation and haskell.lib.compose.overrideCabal
+  # do not allow access to `doInstallCheck` or `nativeInstallCheckInputs`,
+  # so we override directly with `.overrideAttrs`.
+  lateOverrides = finalAttrs: prevAttrs: {
+    doInstallCheck = stdenv.buildPlatform.canExecute stdenv.hostPlatform;
+    nativeInstallCheckInputs = prevAttrs.nativeInstallCheckInputs or [ ] ++ [
+      versionCheckHook
+    ];
+  };
+
   raw-pkg = haskellPackages.callPackage ./generated-package.nix { };
 in
 lib.pipe raw-pkg [
-  (overrideCabal overrides)
+  (overrideCabal cabalOverrides)
   justStaticExecutables
+  (drv: drv.overrideAttrs lateOverrides)
 ]