graph-tool: 2.16 -> 2.26

- add ncurses: configure links against ncurses and fails otherwise
    configure: error: Could not link test program to Python.
    https://travis-ci.org/NixOS/nixpkgs/builds/48759067
    The given hint (Maybe the main Python library has been installed
    in some non-standard library path) is misleading.
    The config.log reveals that the failure is due to missing ncurses link option
- with-boost-libdir is need to find Boost::IOStreams/regex/etc.
- expat/cgal are detected in /usr/lib when not specified explicitly
- boost > boost159 is needed to have -lboost_python3 (and -lboost_python)

- set pythonModule = Python;
  => inorder to be used in python.buildEnv { extraLibs = [..]; }

tested on MacOSX and in a linux Docker container with:
> nix-shell -I nixpkgs=. -p python2.pkgs.graph-tool
> nix-shell -I nixpkgs=. -p python3.pkgs.graph-tool

pkgs/development/python-modules/graph-tool/2.x.x.nix

@@ -1,11 +1,13 @@
 { stdenv, fetchurl, python, cairomm, sparsehash, pycairo, autoreconfHook,
 pkgconfig, boost, expat, scipy, numpy, cgal, gmp, mpfr, lndir,
-gobjectIntrospection, pygobject3, gtk3, matplotlib }:
+gobjectIntrospection, pygobject3, gtk3, matplotlib, ncurses }:
 
 stdenv.mkDerivation rec {
-  version = "2.16";
+  version = "2.26";
   name = "${python.libPrefix}-graph-tool-${version}";
 
+  pythonModule = python;
+
   meta = with stdenv.lib; {
     description = "Python module for manipulation and statistical analysis of graphs";
     homepage    = http://graph-tool.skewed.de/;
@@ -16,16 +18,19 @@ stdenv.mkDerivation rec {
 
   src = fetchurl {
     url = "https://downloads.skewed.de/graph-tool/graph-tool-${version}.tar.bz2";
-    sha256 = "03b1pmh2gvsgyq491gvskx8fwgqy9k942faymdnhwpbbbfhx911p";
+    sha256 = "0w7pd2h8ayr88kjl82c8fdshnk6f3xslc77gy7ma09zkbvf76qnz";
   };
 
   configureFlags = [
     "--with-python-module-path=$(out)/${python.sitePackages}"
+    "--with-boost-libdir=${boost}/lib"
+    "--with-expat=${expat}"
+    "--with-cgal=${cgal}"
     "--enable-openmp"
   ];
 
   nativeBuildInputs = [ autoreconfHook pkgconfig ];
-  buildInputs = [ ];
+  buildInputs = [ ncurses ];
 
   propagatedBuildInputs = [
     boost

pkgs/top-level/python-packages.nix

@@ -7970,9 +7970,7 @@ in {
     };
   };
 
-  # py3k disabled, see https://travis-ci.org/NixOS/nixpkgs/builds/48759067
+  graph-tool = callPackage ../development/python-modules/graph-tool/2.x.x.nix { };
-  graph-tool = if isPy3k then throw "graph-tool in Nix doesn't support py3k yet"
-    else callPackage ../development/python-modules/graph-tool/2.x.x.nix { boost = pkgs.boost159; };
 
   grappelli_safe = buildPythonPackage rec {
     version = "0.3.13";