python310Packages.purepng: fix build

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

@@ -32,10 +32,20 @@ buildPythonPackage {
 
   # numpy is optional - if not supplied, tests simply have less coverage
   nativeCheckInputs = [ numpy ];
+
+  postPatch = ''
+    substituteInPlace code/test_png.py \
+      --replace numpy.bool bool
+  '';
+
   # checkPhase begins by deleting source dir to force test execution against installed version
   checkPhase = ''
+    runHook preCheck
+
     rm -r code/png
     ${python.interpreter} code/test_png.py
+
+    runHook postCheck
   '';
 
   meta = with lib; {
@@ -44,5 +54,4 @@ buildPythonPackage {
     license = licenses.mit;
     maintainers = with maintainers; [ ris ];
   };
-
 }