Tumblr-video downloads fail with 403 errors

[adiabatic]

Checklist

• I'm reporting a broken site support
• I've verified that I'm running youtube-dl version 2019.10.29
• 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 issues including closed ones

Verbose log

$ youtube-dl -v https://aw-hawkeye-yes.tumblr.com/post/188329832256/brought-to-you-by-the-letter-r
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: [u'-v', u'https://aw-hawkeye-yes.tumblr.com/post/188329832256/brought-to-you-by-the-letter-r']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.10.29
[debug] Python version 2.7.16 (CPython) - Darwin-19.0.0-x86_64-i386-64bit
[debug] exe versions: none
[debug] Proxy map: {}
[Tumblr] 188329832256: Downloading webpage
[Tumblr] 188329832256: Downloading iframe page
ERROR: Unable to download webpage: HTTP Error 403: Forbidden (caused by HTTPError()); 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.
  File "/usr/local/bin/youtube-dl/youtube_dl/extractor/common.py", line 627, in _request_webpage
    return self._downloader.urlopen(url_or_request)
  File "/usr/local/bin/youtube-dl/youtube_dl/YoutubeDL.py", line 2237, in urlopen
    return self._opener.open(req, timeout=self._socket_timeout)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 435, in open
    response = meth(req, response)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 548, in http_response
    'http', request, response, code, msg, hdrs)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 473, in error
    return self._call_chain(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 407, in _call_chain
    result = func(*args)
  File "/System/Library/Frameworks/Python.framework/Versions/2.7/lib/python2.7/urllib2.py", line 556, in http_error_default
    raise HTTPError(req.get_full_url(), code, msg, hdrs, fp)

Description

I saw this video in my browser. I wanted to save a copy, so I fed the post's URL into youtube-dl. It didn't download. The video I'm interested in is from Saturday Night Live, which may or may not be relevant.

#22755 doesn't seem to describe this problem because I don't have a Tumblr account and I can view the post (and video) just fine without signing in.

Oddly enough, right-clicking on the playing video in Safari and selecting "Download video" works just fine. It gets me a file called tumblr_pzc3yzjaIc1rmamzg.mp4.

[adiabatic]

One possibility: youtube-dl is trying to snag a video lower down in the page, not the one I'm interested in. I tried right-clicking on the video of Patrick Stewart holding a carved-out letter B, selected "Open Frame in New Window", and was directed to https://www.tumblr.com/video/aw-hawkeye-yes/182979200552/700/, which gave me a Request Denied page. When I looked at the network-transfer tab of Safari's debug tools, it said that this page's status was 403, not 200.