safaribooksonline.com: "Unable to extract kaltura reference id" (RegexNotFoundError)

[benklaasen]

Hi - this bug appears to be a follow-on from the fix for #7491 "Safaribooksonline - ERROR: brightcove said: This player is not enabled for access without key." Thank you @dstftw for addressing that issue!

I have a subscription to safaribooksonline.com and when I go to fetch a playlist, I now get the following error. The complete transaction is listed below:

$ youtube-dl --verbose --username redacted_username --password redacted_password "https://www.safaribooksonline.com/library/view/learn-more-python/9780134096636/"
[debug] System config: []
[debug] User config: []
[debug] Command-line args: [u'--verbose', u'--username', u'PRIVATE', u'--password', u'PRIVATE', u'https://www.safaribooksonline.com/library/view/learn-more-python/9780134096636/']
[debug] Encodings: locale UTF-8, fs UTF-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2016.03.14
[debug] Python version 2.7.10 - Linux-4.2.0-34-generic-x86_64-with-Ubuntu-15.10-wily
[debug] exe versions: ffmpeg 2.7.6-0ubuntu0.15.10.1, ffprobe 2.7.6-0ubuntu0.15.10.1
[debug] Proxy map: {}
[safari:course] Downloading login form
[safari:course] Logging in as redacted_username
[safari:course] Login successful
[safari:course] 9780134096636: Downloading course JSON
[download] Downloading playlist: Learn More Python the Hard Way
[safari:course] playlist Learn More Python the Hard Way: Collected 37 video ids (downloading 37 of them)
[download] Downloading video 1 of 37
[safari] 9780134096636/part00: Downloading webpage
ERROR: Unable to extract kaltura reference id; 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/local/lib/python2.7/dist-packages/youtube_dl/YoutubeDL.py", line 668, in extract_info
    ie_result = ie.extract(url)
  File "/usr/local/lib/python2.7/dist-packages/youtube_dl/extractor/common.py", line 320, in extract
    return self._real_extract(url)
  File "/usr/local/lib/python2.7/dist-packages/youtube_dl/extractor/safari.py", line 115, in _real_extract
    reference_id = self._search_regex(r'data-reference-id="([^"]+)"', webpage, 'kaltura reference id')
  File "/usr/local/lib/python2.7/dist-packages/youtube_dl/extractor/common.py", line 621, in _search_regex
    raise RegexNotFoundError('Unable to extract %s' % _name)
RegexNotFoundError: Unable to extract kaltura reference id; 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.

Let me know if there's anything I can do to help. Thanks!