yt-dlp has new requirements for YouTube downloads

[benoit74]

See yt-dlp/yt-dlp#14404

[kelson42]

Nice.... :(

[rgaudin]

Ah it's the same one @Popolechien mentioned 6w ago ; I was afraid there was yet again new reqs.

[benoit74]

There are new reqs, but "luckily" they are well packaged and supposed to be very small, so we should have nothing to do besides installing proper extra.

[chapmanjacobd]

so we should have nothing to do besides installing proper extra

This link is a bit more clear/up-to-date: https://github.com/yt-dlp/yt-dlp/wiki/EJS

That is, besides yt-dlp[default] (which pulls in yt-dlp-ejs), you might also need to install a javascript runtime if you don't have one already. Deno works out of the box but the others require passing specific configuration to enable

[benoit74]

Thank you @chapmanjacobd , looks like we indeed miss the javascript runtime in linked PR.

Do you know where one can find documentation about how to test if yt-dlp has all required stuff to use the new challenge solver? Is there a reliable way to check this?

[chapmanjacobd]

If you run something like this yt-dlp -vvF https://m.youtube.com/watch?v=uFI5WpK2sgg

you should see these lines:

...
[debug] yt-dlp version nightly@2025.11.03.233024 from yt-dlp/yt-dlp-nightly-builds [ffb7b7f44] (pip)
...
[debug] Optional libraries: ..., yt_dlp_ejs-0.3.0
...
[debug] JS runtimes: deno-2.5.6
...
[debug] [youtube] [jsc] JS Challenge Providers: bun (unavailable), deno, node (unavailable), quickjs (unavailable)
...
[youtube] [jsc:deno] Solving JS challenges using deno
[debug] [youtube] [jsc:deno] Using challenge solver lib script v0.3.0 (source: python package, variant: minified)
[debug] [youtube] [jsc:deno] Using challenge solver core script v0.3.0 (source: python package, variant: minified)
[debug] [youtube] [jsc:deno] Running deno: deno run --ext=js --no-code-cache --no-prompt --no-remote --no-lock --node-modules-dir=none --no-config --no-npm --cached-only -
...

deno just needs to be in the PATH somewhere, similar to the ffmpeg dependency

[benoit74]

I've tested and I can confirm that installation both yt-dlp[default] and deno>=2.0,<3.0 allows to download youtube videos correctly again, except that deno python dependency is not recommend + does not chmod +x deno dependency...

I now consider we should not make this move to add these in python-scraperlib, at least not for now.

deno is a 108M dependency as of 2.5.6. And default extra of yt-dlp probably adds some size as well.

This is just too much size for most scrapers which don't care about yt-dlp, and not about youtube. And since there is no need to add any code in the scraperlib, there is not much incentive to do so.

I recommend we wait for #244 to do that in a better way. Until then, scrapers interested by youtube downloads (only youtube, ted and openedx - sic - scrapers) should install yt-dlp[default] and deno>=2.0,<3.0 on their own. I would just add a warning in the scraperlib README for now.

@rgaudin WDYT?

[rgaudin]

OK, maybe a runtime warning when using video module?

[benoit74]

youtube-dlp already issues a warning when it downloads from youtube but misses the Javascript runtime ... this is far superior (because way more precise) than anything we could do in the scraperlib.

See https://farm.openzim.org/pipeline/08152988-b346-4219-8c04-8c44a6fb8574/debug logs ... which are quite explicit about the fact that we need to release youtube scraper again 🤣

[rgaudin]

Perfect