From 8f5981df31dd075f513351d4cd22d3112684bc47 Mon Sep 17 00:00:00 2001
From: Tyson Whitehead <twhitehead@gmail.com>
Date: Fri, 10 Aug 2018 00:24:19 -0400
Subject: [PATCH] pythonPackages: Implement overlay infrastructure

Accumulate overlays in pythonOverrides attribute and then apply
them just once to base python packages.

https://github.com/NixOS/nixpkgs/issues/44426
---
 pkgs/all-packages.nix         | 2 ++
 pkgs/python-packages.nix      | 3 +++
 temporary/all-temporary.nix   | 7 +++++++
 temporary/python-packages.nix | 3 +++
 4 files changed, 15 insertions(+)
 create mode 100644 pkgs/python-packages.nix
 create mode 100644 temporary/python-packages.nix

diff --git a/pkgs/all-packages.nix b/pkgs/all-packages.nix
index 15f84f5..bd388c6 100644
--- a/pkgs/all-packages.nix
+++ b/pkgs/all-packages.nix
@@ -35,6 +35,8 @@ self: super: pkgs: with pkgs; {
 
   ovito = libsForQt5.callPackage ./ovito.nix { stdenv = overrideCC stdenv gcc6; };
 
+  pythonOverrides = lib.composeExtensions super.pythonOverrides (import ./python-packages.nix pkgs);
+
   #sumo = callPackage ./sumo.nix { fox = fox_1_6; };
 
   namd = callPackage ./namd.nix { };
diff --git a/pkgs/python-packages.nix b/pkgs/python-packages.nix
new file mode 100644
index 0000000..ad9000e
--- /dev/null
+++ b/pkgs/python-packages.nix
@@ -0,0 +1,3 @@
+pkgs: self: super: with self; {
+
+}
diff --git a/temporary/all-temporary.nix b/temporary/all-temporary.nix
index 76fc72b..d16dd73 100644
--- a/temporary/all-temporary.nix
+++ b/temporary/all-temporary.nix
@@ -7,4 +7,11 @@
 
 self: super: pkgs: with pkgs; {
 
+  # https://github.com/NixOS/nixpkgs/issues/44426
+  python27 = super.python27.override { packageOverrides = pythonOverrides; };
+  python34 = super.python34.override { packageOverrides = pythonOverrides; };
+  python35 = super.python35.override { packageOverrides = pythonOverrides; };
+  python36 = super.python36.override { packageOverrides = pythonOverrides; };
+
+  pythonOverrides = import ./python-packages.nix pkgs;
 }
diff --git a/temporary/python-packages.nix b/temporary/python-packages.nix
new file mode 100644
index 0000000..ad9000e
--- /dev/null
+++ b/temporary/python-packages.nix
@@ -0,0 +1,3 @@
+pkgs: self: super: with self; {
+
+}