report traceback on plugin loading for certain verbosities

conda/plugins/manager.py

@@ -104,7 +104,7 @@ def register(self, plugin, name: str | None = None) -> str | None:
             raise PluginError(
                 f"Error while loading conda plugin: "
                 f"{name or self.get_canonical_name(plugin)} ({err})"
-            )
+            ) from err
 
     def load_plugins(self, *plugins) -> int:
         """
@@ -142,9 +142,12 @@ def load_entrypoints(self, group: str, name: str | None = None) -> int:
                     # not using exc_info=True here since the CLI loggers are
                     # set up after CLI initialization and argument parsing,
                     # meaning that it comes too late to properly render
-                    # a traceback
+                    # a traceback; instead we pass exc_info conditionally on
+                    # context.verbosity
+                    kwargs = {"exc_info": err} if context.verbosity >= 2 else {}
                     log.warning(
-                        f"Error while loading conda entry point: {entry_point.name} ({err})"
+                        f"Error while loading conda entry point: {entry_point.name} ({err})",
+                        **kwargs,
                     )
                     continue
 

news/13846-debug-plugin-exceptions

@@ -0,0 +1,19 @@
+### Enhancements
+
+* Report traceback of plugin loading errors with verbosity 2 or higher (`-vv` or more). (#13742 via #13846)
+
+### Bug fixes
+
+* <news item>
+
+### Deprecations
+
+* <news item>
+
+### Docs
+
+* <news item>
+
+### Other
+
+* <news item>