Cookies file in UTF-16 makes youtube-dl exit with code 255 and no debug log

[beatcracker]

Checklist

• I'm reporting a broken site support issue
• I've verified that I'm running youtube-dl version 2020.09.06
• 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 bug reports including closed ones
• I've read bugs section in FAQ

Verbose log

No debug output is displayed.

Description

If cookies file is saved in UTF-16(LE/BE) with or without BOM, youtube-dl will exit with code 255 and no debug log, even if --verbose switch is used. Tested with youtube-dl.exe version 2020.09.06 on Windows Server 2016 x64.

I managed to trigger this issue by using PowerShell ISE to save the file. It defaults to UTF-16LE with BOM.

The closest existing issue I could find is the #5094, but I don't think that it's relevant.