Bug 2480429

Summary: "No supported JavaScript runtime could be found. Only deno is enabled by default;"
Product: [Fedora] Fedora Reporter: Lena Wildervanck <lena>
Component: yt-dlpAssignee: Maxwell G <maxwell>
Status: CLOSED DUPLICATE QA Contact:
Severity: medium Docs Contact:
Priority: unspecified    
Version: 43CC: dominik, maxwell, mikel
Target Milestone: ---   
Target Release: ---   
Hardware: x86_64   
OS: Linux   
URL: https://www.youtube.com/watch?v=dQw4w9WgXcQ
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Last Closed: 2026-06-02 01:54:18 UTC Type: ---
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Description Lena Wildervanck 2026-05-21 11:41:31 UTC 
When downloading a video on YouTube, it shows the warning "WARNING: [youtube] No supported JavaScript runtime could be found. Only deno is enabled by default; to use another runtime add  --js-runtimes RUNTIME[:PATH]  to your command/config. YouTube extraction without a JS runtime has been deprecated, and some formats may be missing. See  https://github.com/yt-dlp/yt-dlp/wiki/EJS  for details on installing one".
Sometimes it will also refuse to download.


Reproducible: Sometimes

Steps to Reproduce:
1. type yt-dlp "https://www.youtube.com/watch?v=dQw4w9WgXcQ"
2. look at the log output.

Actual Results:
Log output contains 
WARNING: [youtube] No supported JavaScript runtime could be found. Only deno is enabled by default; to use another runtime add  --js-runtimes RUNTIME[:PATH]  to your command/config. YouTube extraction without a JS runtime has been deprecated, and some formats may be missing. See  https://github.com/yt-dlp/yt-dlp/wiki/EJS  for details on installing one


Also the video sometimes refuses to download.

Expected Results:
Log output doesn't contain that value. 

Additional Information:
Maybe it's a good idea to add deno as a dependency?
Comment 1 Lena Wildervanck 2026-06-02 01:54:18 UTC 
I swear I searched, but probably a duplicate.

*** This bug has been marked as a duplicate of bug 2405578 ***