From 616f84689437b06d78fadd82e3b3ccf01e9ec7f7 Mon Sep 17 00:00:00 2001
From: Andreas Herrmann <andreash87@gmx.ch>
Date: Fri, 24 Jun 2016 11:50:06 +0200
Subject: [PATCH 1/2] matplotlib: Don't search in global paths

Sets the `basedirlist` option in setup.cfg such that distutils does not search
for headers and libraries in `/usr`, and `/usr/local`.

Otherwise the build can fail on non-NixOS machines, see #15993.
---
 .../python-modules/matplotlib/basedirlist.patch           | 8 ++++++++
 pkgs/development/python-modules/matplotlib/default.nix    | 4 +++-
 2 files changed, 11 insertions(+), 1 deletion(-)
 create mode 100644 pkgs/development/python-modules/matplotlib/basedirlist.patch

diff --git a/pkgs/development/python-modules/matplotlib/basedirlist.patch b/pkgs/development/python-modules/matplotlib/basedirlist.patch
new file mode 100644
index 000000000000..0a84a05bbaea
--- /dev/null
+++ b/pkgs/development/python-modules/matplotlib/basedirlist.patch
@@ -0,0 +1,8 @@
+diff --git a/setup.cfg b/setup.cfg
+new file mode 100644
+index 0000000..6f81985
+--- /dev/null
++++ b/setup.cfg
+@@ -0,0 +1,2 @@
++[directories]
++basedirlist = .
diff --git a/pkgs/development/python-modules/matplotlib/default.nix b/pkgs/development/python-modules/matplotlib/default.nix
index c60ee54bec8e..bba201093a17 100644
--- a/pkgs/development/python-modules/matplotlib/default.nix
+++ b/pkgs/development/python-modules/matplotlib/default.nix
@@ -35,7 +35,9 @@ buildPythonPackage rec {
     ++ stdenv.lib.optional enableGtk2 pygtk
     ++ stdenv.lib.optionals enableGtk3 [ cairo pycairo gtk3 gobjectIntrospection pygobject3 ];
 
-  patches = stdenv.lib.optionals stdenv.isDarwin [ ./darwin-stdenv.patch ];
+  patches =
+    [ ./basedirlist.patch ] ++
+    stdenv.lib.optionals stdenv.isDarwin [ ./darwin-stdenv.patch ];
 
   checkPhase = ''
     ${python.interpreter} tests.py

From ed14f12b89f096ee4f42f1744f3c1a0a17e569f3 Mon Sep 17 00:00:00 2001
From: Andreas Herrmann <andreash87@gmx.ch>
Date: Sun, 5 Jun 2016 13:09:55 +0200
Subject: [PATCH 2/2] matplotlib: Add support for the TkAgg backend

Fixes #15993
---
 .../python-modules/matplotlib/default.nix     | 23 ++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/pkgs/development/python-modules/matplotlib/default.nix b/pkgs/development/python-modules/matplotlib/default.nix
index bba201093a17..72223f6e621e 100644
--- a/pkgs/development/python-modules/matplotlib/default.nix
+++ b/pkgs/development/python-modules/matplotlib/default.nix
@@ -4,11 +4,17 @@
 , enableGhostscript ? false, ghostscript ? null, gtk3
 , enableGtk2 ? false, pygtk ? null, gobjectIntrospection
 , enableGtk3 ? false, cairo
+, enableTk ? false, tcl ? null, tk ? null, tkinter ? null, libX11 ? null
 , Cocoa, Foundation, CoreData, cf-private, libobjc, libcxx
 }:
 
 assert enableGhostscript -> ghostscript != null;
 assert enableGtk2 -> pygtk != null;
+assert enableTk -> (tcl != null)
+                && (tk != null)
+                && (tkinter != null)
+                && (libX11 != null)
+                ;
 
 buildPythonPackage rec {
   name = "matplotlib-${version}";
@@ -33,12 +39,27 @@ buildPythonPackage rec {
       libpng pkgconfig mock pytz  
     ]
     ++ stdenv.lib.optional enableGtk2 pygtk
-    ++ stdenv.lib.optionals enableGtk3 [ cairo pycairo gtk3 gobjectIntrospection pygobject3 ];
+    ++ stdenv.lib.optionals enableGtk3 [ cairo pycairo gtk3 gobjectIntrospection pygobject3 ]
+    ++ stdenv.lib.optionals enableTk [ tcl tk tkinter libX11 ];
 
   patches =
     [ ./basedirlist.patch ] ++
     stdenv.lib.optionals stdenv.isDarwin [ ./darwin-stdenv.patch ];
 
+  # Matplotlib tries to find Tcl/Tk by opening a Tk window and asking the
+  # corresponding interpreter object for its library paths. This fails if
+  # `$DISPLAY` is not set. The fallback option assumes that Tcl/Tk are both
+  # installed under the same path which is not true in Nix.
+  # With the following patch we just hard-code these paths into the install
+  # script.
+  postPatch =
+    let
+      inherit (stdenv.lib.strings) substring;
+      tcl_tk_cache = ''"${tk}/lib", "${tcl}/lib", "${substring 0 3 tk.version}"'';
+    in
+    stdenv.lib.optionalString enableTk
+      "sed -i '/self.tcl_tk_cache = None/s|None|${tcl_tk_cache}|' setupext.py";
+
   checkPhase = ''
     ${python.interpreter} tests.py
   '';