From e68500ff3a25615138fd8428178f9486c4d0f1b0 Mon Sep 17 00:00:00 2001
From: Hamish Mackenzie <Hamish.K.Mackenzie@gmail.com>
Date: Thu, 22 May 2025 13:11:05 +1200
Subject: [PATCH] Use latest `lts` version for `haskel-nix.haskellPackages`

Fixes #2355
---
 overlays/haskell.nix | 9 +++++----
 1 file changed, 5 insertions(+), 4 deletions(-)

diff --git a/overlays/haskell.nix b/overlays/haskell.nix
index 112ce22690..a7fb6e3014 100644
--- a/overlays/haskell.nix
+++ b/overlays/haskell.nix
@@ -170,11 +170,12 @@ final: prev: {
           inherit mkPkgSet stackage excludeBootPackages;
           hackage = hackageForStack;
         };
-        # Pick a recent LTS snapshot to be our "default" package set.
+        # Pick the most recent LTS snapshot to be our "default" package set.
         haskellPackages =
-            if final.stdenv.targetPlatform.isAarch64 && final.stdenv.buildPlatform.isAarch64
-            then snapshots."lts-15.13"
-            else snapshots."lts-14.13";
+          let
+            versions = final.lib.mapAttrsToList
+              (name: _: final.lib.removePrefix "lts-" name) snapshots;
+          in snapshots."lts-${final.lib.head (final.lib.sort final.lib.versionAtLeast versions)}";
 
         # Creates Cabal local repository from { name, index } set.
         mkLocalHackageRepo = import ../mk-local-hackage-repo final;