Fix error when handling VersionConflict exceptions from setuptools entry points

Author: nicoddemus

changelog/160.bugfix.rst

@@ -0,0 +1 @@
+Fix problem when handling ``VersionConflict`` errors when loading setuptools plugins.

pluggy/manager.py

@@ -255,7 +255,8 @@ def load_setuptools_entrypoints(self, entrypoint_name):
                 continue
             except VersionConflict as e:
                 raise PluginValidationError(
-                    "Plugin %r could not be loaded: %s!" % (ep.name, e))
+                    plugin=None,
+                    message="Plugin %r could not be loaded: %s!" % (ep.name, e))
             self.register(plugin, name=ep.name)
             self._plugin_distinfo.append((plugin, ep.dist))
         return len(self._plugin_distinfo)

testing/test_pluginmanager.py

@@ -427,6 +427,28 @@ class PseudoPlugin(object):
     assert pm.list_plugin_distinfo() == [(plugin, None)]
 
 
+def test_load_setuptools_version_conflict(monkeypatch, pm):
+    """Check that we properly handle a VersionConflict problem when loading entry points"""
+    pkg_resources = pytest.importorskip("pkg_resources")
+
+    def my_iter(name):
+        assert name == "hello"
+
+        class EntryPoint(object):
+            name = "myname"
+            dist = None
+
+            def load(self):
+                raise pkg_resources.VersionConflict('Some conflict')
+
+        return iter([EntryPoint()])
+
+    monkeypatch.setattr(pkg_resources, 'iter_entry_points', my_iter)
+    with pytest.raises(PluginValidationError,
+                       match="Plugin 'myname' could not be loaded: Some conflict!"):
+        pm.load_setuptools_entrypoints("hello")
+
+
 def test_load_setuptools_not_installed(monkeypatch, pm):
     monkeypatch.setitem(
         sys.modules, 'pkg_resources',