Comment 5 for bug 1570460

Works fine here. Make sure to connect the "home" plug for allowing it to write the downloaded file.

$ sudo snap connect youtube-dl:home ubuntu-core:home

$ youtube-dl.run ytsearch:ubuntu
WARNING: Assuming --restrict-filenames since file system encoding cannot encode all characters. Set the LC_ALL environment variable to fix this.
[youtube:search] query "ubuntu": Downloading page 1
[download] Downloading playlist: ubuntu
[youtube:search] playlist ubuntu: Collected 1 video ids (downloading 1 of them)
[download] Downloading video 1 of 1
[youtube] fk7OBuoK7ig: Downloading webpage
[youtube] fk7OBuoK7ig: Downloading video info webpage
[youtube] fk7OBuoK7ig: Extracting video information
[youtube] fk7OBuoK7ig: Downloading MPD manifest
[download] Destination: Review_-_Ubuntu_15.04-fk7OBuoK7ig.mp4
[download] 5.9% of 55.15MiB at 865.03KiB/s ETA 01:01
[...]