python.pkgs.pydot: hardcode path to graphviz's bin/

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

@@ -1,9 +1,11 @@
 { lib
 , buildPythonPackage
 , fetchPypi
+, substituteAll
+, graphviz
+, python
 , chardet
 , pyparsing
-, graphviz
 }:
 
 buildPythonPackage rec {
@@ -14,10 +16,29 @@ buildPythonPackage rec {
     inherit pname version;
     sha256 = "02yp2k7p1kh0azwd932jhvfc3nxxdv9dimh7hdgwdnmp05yms6cq";
   };
+
+  patches = [
+    (substituteAll {
+      src = ./hardcode-graphviz-path.patch;
+      inherit graphviz;
+    })
+  ];
+
+  postPatch = ''
+    # test_graphviz_regression_tests also fails upstream: https://github.com/pydot/pydot/pull/198
+    substituteInPlace test/pydot_unittest.py \
+      --replace "test_graphviz_regression_tests" "no_test_graphviz_regression_tests"
+  '';
+
+  propagatedBuildInputs = [ pyparsing ];
+
   checkInputs = [ chardet ];
-  # No tests in archive
-  doCheck = false;
-  propagatedBuildInputs = [pyparsing graphviz];
+
+  checkPhase = ''
+    cd test
+    ${python.interpreter} pydot_unittest.py
+  '';
+
   meta = {
     homepage = https://github.com/erocarrera/pydot;
     description = "Allows to easily create both directed and non directed graphs from Python";

pkgs/development/python-modules/pydot/hardcode-graphviz-path.patch

@@ -0,0 +1,13 @@
+diff --git a/pydot.py b/pydot.py
+index 3c7da4d..582c5bc 100644
+--- a/pydot.py
++++ b/pydot.py
+@@ -124,7 +124,7 @@ def call_graphviz(program, arguments, working_dir, **kwargs):
+         'LD_LIBRARY_PATH': os.environ.get('LD_LIBRARY_PATH', ''),
+     }
+ 
+-    program_with_args = [program, ] + arguments
++    program_with_args = ['@graphviz@/bin/' + program, ] + arguments
+ 
+     process = subprocess.Popen(
+         program_with_args,

pkgs/top-level/python-packages.nix

@@ -3514,7 +3514,9 @@ in {
 
   pydispatcher = callPackage ../development/python-modules/pydispatcher { };
 
-  pydot = callPackage ../development/python-modules/pydot { };
+  pydot = callPackage ../development/python-modules/pydot {
+    inherit (pkgs) graphviz;
+  };
 
   pydot_ng = callPackage ../development/python-modules/pydot_ng { };