error : No supported JavaScript runtime could be found (docker)

[weppami]

cannot solve this error :

time="2025-12-29T16:20:04Z" level=info msg="! downloading episode https://youtube.com/watch?v=4JQJWF5B3T8" episode_id=4JQJWF5B3T8 index=0
time="2025-12-29T16:20:09Z" level=error msg="youtube-dl error: /tmp/podsync-3848206248/4JQJWF5B3T8.%(ext)s" error="failed to execute youtube-dl: exit status 1"
time="2025-12-29T16:20:09Z" level=error msg="[youtube] Extracting URL: https://youtube.com/watch?v=4JQJWF5B3T8\n[youtube] 4JQJWF5B3T8: Downloading webpage\nWARNING: [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\n[youtube] 4JQJWF5B3T8: Downloading android sdkless player API JSON\n[youtube] 4JQJWF5B3T8: Downloading web safari player API JSON\nWARNING: [youtube] No title found in player responses; falling back to title from initial data. Other metadata may also be missing\nERROR: [youtube] 4JQJWF5B3T8: Sign in to confirm you’re not a bot. Use --cookies-from-browser or --cookies for the authentication. See https://github.com/yt-dlp/yt-dlp/wiki/FAQ#how-do-i-pass-cookies-to-yt-dlp for how to manually pass cookies. Also see https://github.com/yt-dlp/yt-dlp/wiki/Extractors#exporting-youtube-cookies for tips on effectively exporting YouTube cookies\n"

Any clues ?

Thanks

[mxpv]

Which podsync version do you use?
Have you tried nightly?

[z66n]

Which podsync version do you use? Have you tried nightly?

I too have encountered this error when using this image: ghcr.io/mxpv/podsync, nightly is working fine though, thanks!

[mxpv]

Sounds like youtube-dl needs an update and the nightly build already includes a newer one.

Try adding this to your configuration:

# Youtube-dl specific configuration.
[downloader]
# Optional, auto update youtube-dl every 24 hours
self_update = true

and restart the container.
This will force podsync to update new youtube-dl version to boot.

[z66n]

I just tried adding the configuration with the ghcr.io/mxpv/podsync and got the below message

time="2026-01-08T03:42:40Z" level=info msg="updating youtube-dl"
time="2026-01-08T03:42:49Z" level=error msg="[debug] Command-line config: ['--update', '--verbose']\n[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8 (No ANSI), error utf-8 (No ANSI), screen utf-8 (No ANSI)\n[debug] yt-dlp version stable@2025.06.30 from yt-dlp/yt-dlp [b01878449] (zip)\n[debug] Python 3.12.9 (CPython x86_64 64bit) - Linux-6.12.43+deb12-amd64-x86_64-with (OpenSSL 3.3.3 11 Feb 2025)\n[debug] exe versions: ffmpeg 6.1.2 (setts), ffprobe 6.1.2\n[debug] Optional libraries: sqlite3-3.48.0\n[debug] Proxy map: {}\n[debug] Request Handlers: urllib\n[debug] Plugin directories: none\n[debug] Loaded 1857 extractors\n[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest\n[debug] Downloading _update_spec from https://github.com/yt-dlp/yt-dlp/releases/latest/download/_update_spec\nERROR: Unable to fetch update spec: [Errno -3] Try again; visit  https://github.com/yt-dlp/yt-dlp/releases/latest\n" error="failed to execute youtube-dl: exit status 100"
time="2026-01-08T03:42:49Z" level=error msg="failed to update youtube-dl" error="failed to self update youtube-dl: failed to execute youtube-dl: exit status 100"

[jochenBoekenheide]

I also get the error:
WARNING: [youtube] 7q-YdQ-FV1Y: n challenge solving failed: Some formats may be missing. Ensure you have a supported JavaScript runtime and challenge solver script distribution installed. Review any warnings presented before this message. For more details, refer to https://github.com/yt-dlp/yt-dlp/wiki/EJS

and then later
[youtube] 7q-YdQ-FV1Y: Downloading m3u8 information
[info] Testing format 96-17
ERROR:
[download] Got error: HTTP Error 403: Forbidden
ERROR: fragment 1 not found, unable to continue
WARNING: Unable to download format 96-17. Skipping...
[info] Testing format 96-16

I also get this error:
youtube-dl error: /tmp/podsync-530705650/7q-YdQ-FV1Y.%(ext)s �[31merror�[0m="failed to execute youtube-dl: exit status 1"

The latest ytd version is installed:
[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest
[debug] Downloading _update_spec from https://github.com/yt-dlp/yt-dlp/releases/latest/download/_update_spec
[debug] Downloading SHA2-256SUMS from https://github.com/yt-dlp/yt-dlp/releases/download/2025.12.08/SHA2-256SUMS
Current version: stable@2025.06.09 from yt-dlp/yt-dlp
Latest version: stable@2025.12.08 from yt-dlp/yt-dlp
Current Build Hash: efba94b3be7911b96bf35bb7437dcf218ab7d244def6d57982af5609f9aeeeb0
Updating to stable@2025.12.08 from yt-dlp/yt-dlp ...
[debug] Downloading yt-dlp from https://github.com/yt-dlp/yt-dlp/releases/download/2025.12.08/yt-dlp
Updated yt-dlp to stable@2025.12.08 from yt-dlp/yt-dlp

Can you help me?

[bw4518]

I am able to download audio with custom_format = { youtube_dl_format = "bestaudio[ext=m4a]", extension = "m4a" } so far, but in general yt-dlp will now need to have Deno (one of the options) installed as well in order to work (as suggested in WARNING).

[nilsstreedain]

Manually setting yt-dlp args to force it to 360p (youtube_dl_args = ["-f", "18"]) technically works for me, but it's 360p. Otherwise looks like we may be stuck until the podsync image is updated to include Deno?

[chkuendig]

#777 added this dependency, so in theory it should be enough to just build from main instead of using the pre-built image.

[colaH16]

nightly and self update all not works.

nightli logs

time="2026-03-01T23:17:19+09:00" level=info msg="running podsync" arch=amd64 commit= date="Thu Feb 26 00:07:39 UTC 2026" version=nightly
time="2026-03-01T23:17:19+09:00" level=info msg="Found PODSYNC_YOUTUBE_API_KEY environment variable, replacing config token with it"
time="2026-03-01T23:17:21+09:00" level=info msg="using youtube-dl 2026.02.21\n"
time="2026-03-01T23:17:21+09:00" level=info msg="found ffmpeg: ffmpeg version 6.1.2 Copyright (c) 2000-2024 the FFmpeg developers\nbuilt with gcc 14.2.0 (Alpine 14.2.0)\nconfiguration: --prefix=/usr --disable-librtmp --disable-lzma --disable-static --disable-stripping --enable-avfilter --enable-gpl --enable-ladspa --enable-libaom --enable-libass --enable-libbluray --enable-libdav1d --enable-libdrm --enable-libfontconfig --enable-libfreetype --enable-libfribidi --enable-libharfbuzz --enable-libmp3lame --enable-libopenmpt --enable-libopus --enable-libplacebo --enable-libpulse --enable-librav1e --enable-librist --enable-libsoxr --enable-libsrt --enable-libssh --enable-libtheora --enable-libv4l2 --enable-libvidstab --enable-libvorbis --enable-libvpx --enable-libwebp --enable-libx264 --enable-libx265 --enable-libxcb --enable-libxml2 --enable-libxvid --enable-libzimg --enable-libzmq --enable-lto=auto --enable-lv2 --enable-openssl --enable-pic --enable-postproc --enable-pthreads --enable-shared --enable-vaapi --enable-vdpau --enable-version3 --enable-vulkan --optflags=-O3 --enable-libjxl --enable-libsvtav1 --enable-libvpl\nlibavutil      58. 29.100 / 58. 29.100\nlibavcodec     60. 31.102 / 60. 31.102\nlibavformat    60. 16.100 / 60. 16.100\nlibavdevice    60.  3.100 / 60.  3.100\nlibavfilter     9. 12.100 /  9. 12.100\nlibswscale      7.  5.100 /  7.  5.100\nlibswresample   4. 12.100 /  4. 12.100\nlibpostproc    57.  3.100 / 57.  3.100\n"
time="2026-03-01T23:17:21+09:00" level=info msg="updating youtube-dl"
time="2026-03-01T23:17:24+09:00" level=info msg="[debug] Command-line config: ['--update', '--verbose']\n[debug] Encodings: locale UTF-8, fs utf-8, pref UTF-8, out utf-8 (No ANSI), error utf-8 (No ANSI), screen utf-8 (No ANSI)\n[debug] yt-dlp version stable@2026.02.21 from yt-dlp/yt-dlp [646bb31f3] (zip)\n[debug] Python 3.12.12 (CPython x86_64 64bit) - Linux-6.18.8-1.0.10.sr20260101-default-x86_64-with (OpenSSL 3.5.5 27 Jan 2026)\n[debug] exe versions: ffmpeg 6.1.2 (setts), ffprobe 6.1.2\n[debug] Optional libraries: sqlite3-3.49.2, yt_dlp_ejs-0.5.0\n[debug] JS runtimes: deno-2.3.1\n[debug] Proxy map: {}\n[debug] Request Handlers: urllib\n[debug] Plugin directories: none\n[debug] Loaded 1864 extractors\n[debug] Fetching release info: https://api.github.com/repos/yt-dlp/yt-dlp/releases/latest\nLatest version: stable@2026.02.21 from yt-dlp/yt-dlp\nyt-dlp is up to date (stable@2026.02.21 from yt-dlp/yt-dlp)\n"
time="2026-03-01T23:17:24+09:00" level=info msg="opening database \"db\""
time="2026-03-01T23:17:24+09:00" level=info msg="All 0 tables opened in 0s\n"
time="2026-03-01T23:17:24+09:00" level=info msg="running listener at :8080"

and done. nothing.
2.8.0 logs

time="2026-03-01T23:19:26+09:00" level=info msg="! downloading episode https://youtube.com/watch?v=-4XLOUXx2i8" episode_id=-4XLOUXx2i8 index=0
time="2026-03-01T23:19:30+09:00" level=error msg="youtube-dl error: /tmp/podsync-4166513870/-4XLOUXx2i8.%(ext)s" error="failed to execute youtube-dl: exit status 1"
time="2026-03-01T23:19:30+09:00" level=error msg="[youtube] Extracting URL: https://youtube.com/watch?v=-4XLOUXx2i8\n[youtube] -4XLOUXx2i8: Downloading webpage\n[youtube] -4XLOUXx2i8: Downloading tv downgraded player API JSON\n[youtube] -4XLOUXx2i8: Downloading web creator player API JSON\nWARNING: [youtube] -4XLOUXx2i8: n challenge solving failed: Some formats may be missing. Ensure you have a supported JavaScript runtime and challenge solver script distribution installed. Review any warnings presented before this message. For more details, refer to  https://github.com/yt-dlp/yt-dlp/wiki/EJS\nWARNING: Only images are available for download. use --list-formats to see them\nERROR: [youtube] -4XLOUXx2i8: Requested format is not available. Use --list-formats for a list of available formats\n"
time="2026-03-01T23:19:30+09:00" level=info msg="! downlo