Make ExtractorError usable for other causes

youtube_dl/FileDownloader.py

@@ -216,12 +216,15 @@ class FileDownloader(object):
         Depending on if the downloader has been configured to ignore
         download errors or not, this method may throw an exception or
         not when errors are found, after printing the message.
+
+        tb, if given, is additional traceback information.
         """
         if message is not None:
             self.to_stderr(message)
         if self.params.get('verbose'):
             if tb is None:
-                tb = u''.join(traceback.format_list(traceback.extract_stack()))
+                tb_data = traceback.format_list(traceback.extract_stack())
+                tb = u''.join(tb_data)
             self.to_stderr(tb)
         if not self.params.get('ignoreerrors', False):
             raise DownloadError(message)
@@ -497,7 +500,7 @@ class FileDownloader(object):
                 try:
                     videos = ie.extract(url)
                 except ExtractorError as de: # An error we somewhat expected
-                    self.trouble(u'ERROR: ' + compat_str(de), compat_str(u''.join(traceback.format_tb(de.traceback))))
+                    self.trouble(u'ERROR: ' + compat_str(de), de.format_traceback())
                     break
                 except Exception as e:
                     if self.params.get('ignoreerrors', False):

youtube_dl/InfoExtractors.py

@@ -117,7 +117,7 @@ class InfoExtractor(object):
         except (compat_urllib_error.URLError, compat_http_client.HTTPException, socket.error) as err:
             if errnote is None:
                 errnote = u'Unable to download webpage'
-            raise ExtractorError(u'%s: %s' % (errnote, compat_str(err)))
+            raise ExtractorError(u'%s: %s' % (errnote, compat_str(err)), sys.exc_info()[2])
 
 
 class YoutubeIE(InfoExtractor):

youtube_dl/utils.py

@@ -8,6 +8,7 @@ import locale
 import os
 import re
 import sys
+import traceback
 import zlib
 import email.utils
 import json
@@ -414,12 +415,15 @@ def encodeFilename(s):
 class ExtractorError(Exception):
     """Error during info extraction."""
     def __init__(self, msg, tb=None):
-        """ tb is the original traceback (so that it can be printed out) """
+        """ tb, if given, is the original traceback (so that it can be printed out). """
         super(ExtractorError, self).__init__(msg)
-        if tb is None:
-            tb = sys.exc_info()[2]
         self.traceback = tb
 
+    def format_traceback(self):
+        if self.traceback is None:
+            return None
+        return u''.join(traceback.format_tb(self.traceback))
+
 
 class DownloadError(Exception):
     """Download Error exception.