bug while try to download the video

[akhmadcoder]

Hi there, I have a link which is https://www.youtube.com/watch?v=8d_ubndKgDc&feature=youtu.be

When I try to download from terminal in mac as: youtube-dl https://www.youtube.com/watch?v=8d_ubndKgDc it reports me the following error message:
ERROR: Signature extraction failed: Traceback (most recent call last):
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
video_id, player_url, s
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
res = self._parse_sig_js(code)
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
jscode, 'Initial JS player signature function name', group='sig')
File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 1004, in _search_regex
raise RegexNotFoundError('Unable to extract %s' % _name)
RegexNotFoundError: Unable to extract Initial JS player signature function name; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type youtube-dl -U to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
(caused by RegexNotFoundError(u'Unable to extract \x1b[0;34mInitial JS player signature function name\x1b[0m; please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type youtube-dl -U to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.',)); please report this issue on https://yt-dl.org/bug . Make sure you are using the latest version; type youtube-dl -U to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

please fix your bug if it is bug.
regards
Akhmad