[Youtube] Signature extraction failed

[tokyovigilante]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2019.06.08
• I've checked that all provided URLs are alive and playable in a browser
• I've checked that all URLs and arguments with special characters are properly quoted or escaped
• I've searched the bugtracker for similar bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

youtube-dl --verbose https://www.youtube.com/watch?v=LGjt291COa0
[debug] System config: ['--prefer-free-formats']
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--verbose', 'https://www.youtube.com/watch?v=LGjt291COa0']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.06.08
[debug] Python version 3.7.3 (CPython) - Linux-5.1.8-300.fc30.x86_64-x86_64-with-fedora-30-Thirty
[debug] exe versions: ffmpeg 4.1.3, ffprobe 4.1.3
[debug] Proxy map: {}
[youtube] LGjt291COa0: Downloading webpage
[youtube] LGjt291COa0: Downloading video info webpage
[youtube] {18} signature length 104, html5 player vfl49f_g4
[youtube] LGjt291COa0: Downloading player https://www.youtube.com/yts/jsbin/player_ias-vfl49f_g4/en_US/base.js
ERROR: Signature extraction failed: Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1005, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.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; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
 (caused by RegexNotFoundError('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; see  https://yt-dl.org/update  on how 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; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1005, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.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; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1005, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.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; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

During handling of the above exception, another exception occurred:

Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/youtube_dl/YoutubeDL.py", line 795, in extract_info
    ie_result = ie.extract(url)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 530, in extract
    ie_result = self._real_extract(url)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1986, in _real_extract
    encrypted_sig, video_id, player_url, age_gate)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1352, in _decrypt_signature
    'Signature extraction failed: ' + tb, cause=e)
youtube_dl.utils.ExtractorError: Signature extraction failed: Traceback (most recent call last):
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1342, in _decrypt_signature
    video_id, player_url, s
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1250, in _extract_signature_function
    res = self._parse_sig_js(code)
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/youtube.py", line 1314, in _parse_sig_js
    jscode, 'Initial JS player signature function name', group='sig')
  File "/usr/lib/python3.7/site-packages/youtube_dl/extractor/common.py", line 1005, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
youtube_dl.utils.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; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.
 (caused by RegexNotFoundError('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; see  https://yt-dl.org/update  on how 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; see  https://yt-dl.org/update  on how to update. Be sure to call youtube-dl with the --verbose flag and include its complete output.

Description

Trying to play this youtube video via mpv and directly with youtube-dl.

[phoenixatom]

Pinging @dstftw in case you haven't seen this

[arisboch]

Can confirm that