[youtube] Include video Id in common error message (Fixes #2786)

youtube_dl/extractor/youtube.py

@@ -1082,9 +1082,13 @@ class YoutubeIE(YoutubeBaseInfoExtractor, SubtitlesInfoExtractor):
                     break
         if 'token' not in video_info:
             if 'reason' in video_info:
-                raise ExtractorError(u'YouTube said: %s' % video_info['reason'][0], expected=True)
+                raise ExtractorError(
+                    u'YouTube said: %s' % video_info['reason'][0],
+                    expected=True, video_id=video_id)
             else:
-                raise ExtractorError(u'"token" parameter not in video info for unknown reason')
+                raise ExtractorError(
+                    u'"token" parameter not in video info for unknown reason',
+                    video_id=video_id)
 
         if 'view_count' in video_info:
             view_count = int(video_info['view_count'][0])

youtube_dl/utils.py

@@ -594,13 +594,15 @@ def make_HTTPS_handler(opts_no_check_certificate, **kwargs):
 
 class ExtractorError(Exception):
     """Error during info extraction."""
-    def __init__(self, msg, tb=None, expected=False, cause=None):
+    def __init__(self, msg, tb=None, expected=False, cause=None, video_id=None):
         """ tb, if given, is the original traceback (so that it can be printed out).
         If expected is set, this is a normal error message and most likely not a bug in youtube-dl.
         """
 
         if sys.exc_info()[0] in (compat_urllib_error.URLError, socket.timeout, UnavailableVideoError):
             expected = True
+        if video_id is not None:
+            msg = video_id + ': ' + msg
         if not expected:
             msg = msg + u'; please report this issue on https://yt-dl.org/bug . Be sure to call youtube-dl with the --verbose flag and include its complete output. Make sure you are using the latest version; type  youtube-dl -U  to update.'
         super(ExtractorError, self).__init__(msg)
@@ -608,6 +610,7 @@ class ExtractorError(Exception):
         self.traceback = tb
         self.exc_info = sys.exc_info()  # preserve original exception
         self.cause = cause
+        self.video_id = video_id
 
     def format_traceback(self):
         if self.traceback is None: