push sheeet

pkgs/test/haskell/env/default.nix

@@ -0,0 +1,55 @@
+{
+  lib,
+  haskellPackages,
+}:
+
+let
+  withEnv =
+    env:
+    haskellPackages.mkDerivation {
+      pname = "puppy";
+      version = "1.0.0";
+      src = null;
+      license = null;
+
+      inherit env;
+    };
+
+  failures = lib.runTests {
+    testCanSetEnv = {
+      expr =
+        (withEnv {
+          PUPPY = "DOGGY";
+        }).drvAttrs.PUPPY;
+      expected = "DOGGY";
+    };
+
+    testCanSetEnvMultiple = {
+      expr =
+        let
+          env =
+            (withEnv {
+              PUPPY = "DOGGY";
+              SILLY = "GOOFY";
+            }).drvAttrs;
+        in
+        {
+          inherit (env) PUPPY SILLY;
+        };
+      expected = {
+        PUPPY = "DOGGY";
+        SILLY = "GOOFY";
+      };
+    };
+
+    testCanSetEnvPassthru = {
+      expr =
+        (withEnv {
+          PUPPY = "DOGGY";
+        }).passthru.env.PUPPY;
+      expected = "DOGGY";
+    };
+  };
+in
+# TODO: Use `lib.debug.throwTestFailures`: https://github.com/NixOS/nixpkgs/pull/416207
+lib.optional (failures != [ ]) (throw "${lib.generators.toPretty { } failures}")