From 0edf0fd22074c2ee178b194203643c19f9fb66d0 Mon Sep 17 00:00:00 2001
From: Robert Hensing <robert@roberthensing.nl>
Date: Sun, 13 Jun 2021 01:10:46 +0200
Subject: [PATCH] hello: Test independence of environment.noXlibs

---
 pkgs/applications/misc/hello/default.nix | 13 +++++++++++--
 1 file changed, 11 insertions(+), 2 deletions(-)

diff --git a/pkgs/applications/misc/hello/default.nix b/pkgs/applications/misc/hello/default.nix
index b446fe6223df..9f1e89c0df6b 100644
--- a/pkgs/applications/misc/hello/default.nix
+++ b/pkgs/applications/misc/hello/default.nix
@@ -1,7 +1,9 @@
 { lib
 , stdenv
 , fetchurl
+, nixos
 , testVersion
+, testEqualDerivation
 , hello
 }:
 
@@ -16,8 +18,15 @@ stdenv.mkDerivation rec {
 
   doCheck = true;
 
-  passthru.tests.version =
-    testVersion { package = hello; };
+  passthru.tests = {
+    version = testVersion { package = hello; };
+
+    invariant-under-noXlibs =
+      testEqualDerivation
+        "hello must not be rebuilt when environment.noXlibs is set."
+        hello
+        (nixos { environment.noXlibs = true; }).pkgs.hello;
+  };
 
   meta = with lib; {
     description = "A program that produces a familiar, friendly greeting";