Merge staging-next into staging

pkgs/development/interpreters/python/cpython/2.7/default.nix

@@ -68,7 +68,7 @@ let
     executable = libPrefix;
     pythonVersion = with sourceVersion; "${major}.${minor}";
     sitePackages = "lib/${libPrefix}/site-packages";
-    inherit hasDistutilsCxxPatch;
+    inherit hasDistutilsCxxPatch pythonAttr;
     pythonOnBuildForBuild = pkgsBuildBuild.${pythonAttr};
     pythonOnBuildForHost = pkgsBuildHost.${pythonAttr};
     pythonOnBuildForTarget = pkgsBuildTarget.${pythonAttr};

pkgs/development/interpreters/python/cpython/default.nix

@@ -91,7 +91,7 @@ let
     executable = libPrefix;
     pythonVersion = with sourceVersion; "${major}.${minor}";
     sitePackages = "lib/${libPrefix}/site-packages";
-    inherit hasDistutilsCxxPatch;
+    inherit hasDistutilsCxxPatch pythonAttr;
     pythonOnBuildForBuild = override pkgsBuildBuild.${pythonAttr};
     pythonOnBuildForHost = override pkgsBuildHost.${pythonAttr};
     pythonOnBuildForTarget = override pkgsBuildTarget.${pythonAttr};

pkgs/development/interpreters/python/default.nix

@@ -19,9 +19,14 @@ with pkgs;
     , pythonOnBuildForTarget
     , pythonOnHostForHost
     , pythonOnTargetForTarget
+    , pythonAttr ? null
     , self # is pythonOnHostForTarget
     }: let
       pythonPackages = callPackage
+        # Function that when called
+        # - imports python-packages.nix
+        # - adds spliced package sets to the package set
+        # - applies overrides from `packageOverrides` and `pythonPackagesOverlays`.
         ({ pkgs, stdenv, python, overrides }: let
           pythonPackagesFun = import ../../../top-level/python-packages.nix {
             inherit stdenv pkgs lib;
@@ -74,7 +79,7 @@ with pkgs;
           extra = _: {};
           optionalExtensions = cond: as: if cond then as else [];
           python2Extension = import ../../../top-level/python2-packages.nix;
-          extensions = lib.composeManyExtensions ((optionalExtensions (!self.isPy3k) [python2Extension]) ++ [ overrides ]);
+          extensions = lib.composeManyExtensions ((optionalExtensions (!self.isPy3k) [python2Extension]) ++ pkgs.pythonPackagesExtensions ++ [ overrides ]);
           aliases = self: super: lib.optionalAttrs config.allowAliases (import ../../../top-level/python-aliases.nix lib self super);
         in lib.makeScopeWithSplicing
           pkgs.splicePackages
@@ -117,6 +122,8 @@ with pkgs;
         tests = callPackage ./tests.nix {
           python = self;
         };
+
+        inherit pythonAttr;
   };
 
   sources = {

pkgs/development/interpreters/python/pypy/default.nix

@@ -30,6 +30,7 @@ let
     executable = "pypy${if isPy3k then "3" else ""}";
     sitePackages = "site-packages";
     hasDistutilsCxxPatch = false;
+    inherit pythonAttr;
 
     pythonOnBuildForBuild = pkgsBuildBuild.${pythonAttr};
     pythonOnBuildForHost = pkgsBuildHost.${pythonAttr};

pkgs/development/interpreters/python/tests.nix

@@ -11,6 +11,7 @@
 , substituteAll
 , lib
 , callPackage
+, pkgs
 }:
 
 let
@@ -133,6 +134,17 @@ let
     # test-overrideScope = let
     #  myPackages = python.pkgs.overrideScope extension;
     # in assert myPackages.foobar == myPackages.numpy; myPackages.python.withPackages(ps: with ps; [ foobar ]);
+  } // lib.optionalAttrs (python ? pythonAttr) {
+    # Test applying overrides using pythonPackagesOverlays.
+    test-pythonPackagesExtensions = let
+      pkgs_ = pkgs.extend(final: prev: {
+        pythonPackagesExtensions = prev.pythonPackagesExtensions ++ [
+          (python-final: python-prev: {
+            foo = python-prev.setuptools;
+          })
+        ];
+      });
+    in pkgs_.${python.pythonAttr}.pkgs.foo;
   };
 
   condaTests = let