diff mercurial/extensions.py @ 25364:de23a552fc23

extensions: show traceback on load failure if --traceback flag is set

Before this patch, there was no handy way to investigate the reason why
extension couldn't be loaded.

If ui.debug is set, tracebacks of both "hgext.foo" and "foo" are displayed
because the first ImportError could occur at very deep dependency module.

--- a/mercurial/extensions.py	Sun May 31 14:40:28 2015 +0900
+++ b/mercurial/extensions.py	Mon Mar 30 16:23:35 2015 +0900
@@ -85,6 +85,8 @@
         except ImportError, err:
             ui.debug('could not import hgext.%s (%s): trying %s\n'
                      % (name, err, name))
+            if ui.debugflag:
+                ui.traceback()
             mod = importh(name)
     _extensions[shortname] = mod
     _order.append(shortname)
@@ -110,6 +112,7 @@
             else:
                 ui.warn(_("*** failed to import extension %s: %s\n")
                         % (name, inst))
+            ui.traceback()
 
     for name in _order[newindex:]:
         uisetup = getattr(_extensions[name], 'uisetup', None)