Show last exception text and NIKOLA_DEBUG explanation (#2774 #2771)

Signed-off-by: Chris Warrick <kwpolska@gmail.com>
getnikola · May 21, 2017 · cc27a4a · cc27a4a
1 parent a54a3e1
commit cc27a4a
Showing 1 changed file with 11 additions and 1 deletion.
diff --git a/nikola/__main__.py b/nikola/__main__.py
@@ -284,9 +284,10 @@ def load_tasks(self, cmd, opt_values, pos_args):
                 self.nikola.gen_tasks('post_render', "LateTask", 'Group of tasks to be executed after site is rendered.'))
             signal('initialized').send(self.nikola)
         except Exception:
-            LOGGER.error('Error loading tasks')
+            LOGGER.error('Error loading tasks. An unhandled exception occurred.')
             if self.nikola.debug:
                 raise
+            _print_exception()
             sys.exit(3)
         return tasks + latetasks, DOIT_CONFIG
 
@@ -372,8 +373,10 @@ def run(self, cmd_args):
         try:
             return super(DoitNikola, self).run(cmd_args)
         except Exception:
+            LOGGER.error('An unhandled exception occurred.')
             if self.nikola.debug:
                 raise
+            _print_exception()
             return 1
 
     @staticmethod
@@ -410,5 +413,12 @@ def levenshtein(s1, s2):
     return previous_row[-1]
 
 
+def _print_exception():
+    """Print an exception in a more friendly, shorter style."""
+    etype, evalue, _ = sys.exc_info()
+    LOGGER.error(''.join(traceback.format_exception(etype, evalue, None, limit=0, chain=False)).strip())
+    LOGGER.notice("To see more details, run Nikola in debug mode (set environment variable NIKOLA_DEBUG=1)")
+
+
 if __name__ == "__main__":
     sys.exit(main(sys.argv[1:]))