pywal: move to pythonPackages and inject path to convert

pkgs/development/python-modules/pywal/default.nix

@@ -0,0 +1,36 @@
+{ lib, python3Packages, imagemagick, feh }:
+
+python3Packages.buildPythonApplication rec {
+  pname = "pywal";
+  version = "3.2.1";
+
+  src = python3Packages.fetchPypi {
+    inherit pname version;
+    sha256 = "1pj30h19ijwhmbm941yzbkgr19q06dhp9492h9nrqw1wfjfdbdic";
+  };
+
+  # necessary for imagemagick to be found during tests
+  buildInputs = [ imagemagick ];
+
+  makeWrapperArgs = [ "--prefix PATH : ${lib.makeBinPath [ imagemagick feh ]}" ];
+
+  preCheck = ''
+    mkdir tmp
+    HOME=$PWD/tmp
+  '';
+
+  patches = [
+    ./convert.patch
+  ];
+
+  postPatch = ''
+    substituteInPlace pywal/backends/wal.py --subst-var-by convert "${imagemagick}/bin/convert"
+  '';
+
+  meta = with lib; {
+    description = "Generate and change colorschemes on the fly. A 'wal' rewrite in Python 3.";
+    homepage = https://github.com/dylanaraps/pywal;
+    license = licenses.mit;
+    maintainers = with maintainers; [ Fresheyeball ];
+  };
+}