From 88ea86a97091d2131171d077977f3699a05ff1fc Mon Sep 17 00:00:00 2001
From: Matt Sturgeon <matt@sturgeon.me.uk>
Date: Wed, 19 Aug 2026 22:54:29 +0100
Subject: [PATCH] maintainers/haskell: format with treefmt config

---
 maintainers/scripts/haskell/regenerate-hackage-packages.sh | 4 ++--
 maintainers/scripts/haskell/update-cabal2nix-unstable.sh   | 4 ++--
 2 files changed, 4 insertions(+), 4 deletions(-)

diff --git a/maintainers/scripts/haskell/regenerate-hackage-packages.sh b/maintainers/scripts/haskell/regenerate-hackage-packages.sh
index d2c5c25c65f8..5033072b385d 100755
--- a/maintainers/scripts/haskell/regenerate-hackage-packages.sh
+++ b/maintainers/scripts/haskell/regenerate-hackage-packages.sh
@@ -1,5 +1,5 @@
 #! /usr/bin/env nix-shell
-#! nix-shell -i bash -p coreutils haskellPackages.cabal2nix-unstable.bin git -I nixpkgs=.
+#! nix-shell -i bash -E 'with import ../../.. {}; mkShell { packages = [ bash coreutils haskellPackages.cabal2nix-unstable.bin git (import ../../../ci {}).fmt.pkg ]; }'
 
 set -euo pipefail
 
@@ -102,7 +102,7 @@ run_hackage2nix
 
 fi
 
-nixfmt pkgs/development/haskell-modules/hackage-packages.nix
+treefmt --no-cache pkgs/development/haskell-modules/hackage-packages.nix
 
 if [[ "$DO_COMMIT" -eq 1 ]]; then
 git add pkgs/development/haskell-modules/configuration-hackage2nix/transitive-broken.yaml
diff --git a/maintainers/scripts/haskell/update-cabal2nix-unstable.sh b/maintainers/scripts/haskell/update-cabal2nix-unstable.sh
index a9f3dc588383..e3c498e98738 100755
--- a/maintainers/scripts/haskell/update-cabal2nix-unstable.sh
+++ b/maintainers/scripts/haskell/update-cabal2nix-unstable.sh
@@ -1,5 +1,5 @@
 #! /usr/bin/env nix-shell
-#! nix-shell -i bash -p coreutils curl jq gnused haskellPackages.cabal2nix-unstable.bin nix-prefetch-scripts -I nixpkgs=.
+#! nix-shell -i bash -E 'with import ../../.. {}; mkShell { packages = [ bash coreutils curl jq gnused haskellPackages.cabal2nix-unstable.bin nix-prefetch-scripts (import ../../../ci {}).fmt.pkg ]; }'
 
 # Updates cabal2nix-unstable to the latest master of the nixos/cabal2nix repository.
 # See regenerate-hackage-packages.sh for details on the purpose of this script.
@@ -18,7 +18,7 @@ function mkPackage() {
   output=pkgs/development/haskell-modules/cabal2nix-unstable/$1.nix
   echo "# This file defines $1-unstable, used by maintainers/scripts/haskell/regenerate-hackage-packages.sh." > "$output"
   cabal2nix --subpath "$1" "https://github.com/NixOS/cabal2nix/archive/$commit.tar.gz" | sed -Ee 's/version = "(.*)"/version = "\1-unstable-'"$date"'"/' >> "$output"
-  nixfmt "$output"
+  treefmt --no-cache "$output"
 }
 
 mkPackage "cabal2nix"