Merge pull request #629 from drdavella/extension-warnings

Provide source information for deprecation warnings from extensions

CHANGES.rst

@@ -6,6 +6,9 @@
 2.3.1 (unreleased)
 ------------------
 
+- Provide source information for ``AsdfDeprecationWarning`` that come from
+  extensions from external packages. [#629]
+
 - Ensure that top-level accesses to the tree outside a closed context handler
   result in an ``OSError``. [#628]
 

asdf/extension.py

@@ -192,7 +192,9 @@ def __init__(self):
 
     def _load_installed_extensions(self, group='asdf_extensions'):
         for entry_point in iter_entry_points(group=group):
-            ext = entry_point.load()
+            with warnings.catch_warnings(record=True) as w:
+                warnings.simplefilter('always', category=AsdfDeprecationWarning)
+                ext = entry_point.load()
             if not issubclass(ext, AsdfExtension):
                 warnings.warn("Found entry point {}, from {} but it is not a "
                               "subclass of AsdfExtension, as expected. It is "
@@ -204,6 +206,10 @@ def _load_installed_extensions(self, group='asdf_extensions'):
             self._package_metadata[name] = (dist.project_name, dist.version)
             self._extensions.append(ext())
 
+            for warning in w:
+                warnings.warn('{} (from {})'.format(warning.message, name),
+                              AsdfDeprecationWarning)
+
     @property
     def extensions(self):
         # This helps avoid a circular dependency with external packages