build.log

these derivations will be built:
  /nix/store/7dbx2dakqj40d4ggr0wyk6ksnkh308m8-git-cola-2.1.0.drv
building path(s) ‘/nix/store/zirh5w5qhwbp1anpm9mjf26v6wkwrcp0-git-cola-2.1.0’
building /nix/store/zirh5w5qhwbp1anpm9mjf26v6wkwrcp0-git-cola-2.1.0
unpacking sources
unpacking source archive /nix/store/a7jka15ygg6yg2jq6vl18qmiidkcfxia-v2.1.0.tar.gz
source root is git-cola-2.1.0
patching sources
configuring
no configure script, doing nothing
building
make flags: SHELL=/nix/store/cxrc12hkmvrjlq747cm08av6jl41nzi1-bash-4.3-p30/bin/bash    
/nix/store/cxrc12hkmvrjlq747cm08av6jl41nzi1-bash-4.3-p30/bin/bash: python: command not found
building all
python setup.py build
/nix/store/cxrc12hkmvrjlq747cm08av6jl41nzi1-bash-4.3-p30/bin/bash: python: command not found
make: *** [all] Error 127
builder for ‘/nix/store/7dbx2dakqj40d4ggr0wyk6ksnkh308m8-git-cola-2.1.0.drv’ failed with exit code 2
error: build of ‘/nix/store/7dbx2dakqj40d4ggr0wyk6ksnkh308m8-git-cola-2.1.0.drv’ failed

git-cola.nix

{ inotify ? true, 
  stdenv, fetchurl, pkgconfig, git, python3, python33Packages, pyqt4, qt4  
}:

stdenv.mkDerivation rec {
  name = "git-cola-${version}";
  version = "2.1.0";
  src = fetchurl {
    url = "https://github.com/git-cola/git-cola/archive/v${version}.tar.gz";
    sha256 = "1a443b270d5a710c60d00b51ccdef7e324a587e0e5e2b5ac9856a1a3d1ec878b";
  };

  pythonPath = with python33Packages; [ argparse sip pyqt4 ]
  ++ stdenv.lib.optional inotify pyinotify;

  buildInputs = [ 
    stdenv pkgconfig python3 git qt4
  ];

  installPhase = ''
    make prefix=$out install
  '';

  meta = {
    homepage = "http://git-cola.github.io/";
    description = "A sleek and powerful Git GUI written in python";
    license = stdenv.lib.licenses.gpl2;
  };
}