From cf3e7fbe5d105f49a44b837da4dd05d391bc6c58 Mon Sep 17 00:00:00 2001
From: Geoff Reedy <geoff@programmer-monk.net>
Date: Wed, 8 Sep 2021 08:06:58 -0600
Subject: [PATCH] mkshell: small fix for #137005

I somehow accidentally left out the lib.flatten from mergeInputs. Without it, subtractLists won't ever remove anything from the inputs since the inputs will be a list of lists.
---
 pkgs/build-support/mkshell/default.nix | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/pkgs/build-support/mkshell/default.nix b/pkgs/build-support/mkshell/default.nix
index f85a11394cb57..27ee7e3226241 100644
--- a/pkgs/build-support/mkshell/default.nix
+++ b/pkgs/build-support/mkshell/default.nix
@@ -16,7 +16,7 @@
 let
   mergeInputs = name:
     (attrs.${name} or []) ++
-    (lib.subtractLists inputsFrom (lib.catAttrs name inputsFrom));
+    (lib.subtractLists inputsFrom (lib.flatten (lib.catAttrs name inputsFrom)));
 
   rest = builtins.removeAttrs attrs [
     "packages"