1 files changed, 15 insertions, 20 deletions
diff --git a/nixpkgs/pkgs/test/nixpkgs-check-by-name/tests/mock-nixpkgs.nix b/nixpkgs/pkgs/test/nixpkgs-check-by-name/tests/mock-nixpkgs.nix
index 01bb27a48038..81a9c916ac2d 100644
--- a/nixpkgs/pkgs/test/nixpkgs-check-by-name/tests/mock-nixpkgs.nix
+++ b/nixpkgs/pkgs/test/nixpkgs-check-by-name/tests/mock-nixpkgs.nix
@@ -19,34 +19,20 @@ It returns a Nixpkgs-like function that can be auto-called and evaluates to an a
   overlays ? [],
   # Passed by the checker to make sure a real Nixpkgs isn't influenced by impurities
   config ? {},
+  # Passed by the checker to make sure a real Nixpkgs isn't influenced by impurities
+  system ? null,
 }:
 let
 
   # Simplified versions of lib functions
-  lib = {
-    fix = f: let x = f x; in x;
-
-    extends = overlay: f: final:
-      let
-        prev = f final;
-      in
-      prev // overlay final prev;
-
-    callPackageWith = autoArgs: fn: args:
-      let
-        f = if builtins.isFunction fn then fn else import fn;
-        fargs = builtins.functionArgs f;
-        allArgs = builtins.intersectAttrs fargs autoArgs // args;
-      in
-      f allArgs;
-
-    isDerivation = value: value.type or null == "derivation";
-  };
+  lib = import <test-nixpkgs/lib>;
 
   # The base fixed-point function to populate the resulting attribute set
   pkgsFun = self: {
     inherit lib;
-    callPackage = lib.callPackageWith self;
+    newScope = extra: lib.callPackageWith (self // extra);
+    callPackage = self.newScope { };
+    callPackages = lib.callPackagesWith self;
     someDrv = { type = "derivation"; };
   };
 
@@ -91,12 +77,21 @@ let
     else
       [ ];
 
+  # A list optionally containing the `aliases.nix` file from the test case as an overlay
+  # But only if config.allowAliases is not false
+  optionalAliasesOverlay =
+    if (config.allowAliases or true) && builtins.pathExists (root + "/aliases.nix") then
+      [ (import (root + "/aliases.nix")) ]
+    else
+      [ ];
+
   # All the overlays in the right order, including the user-supplied ones
   allOverlays =
     [
       autoCalledPackages
     ]
     ++ optionalAllPackagesOverlay
+    ++ optionalAliasesOverlay
     ++ overlays;
 
   # Apply all the overlays in order to the base fixed-point function pkgsFun