Force Overwrite

[wangqr]

Checklist

• [ ] I'm reporting a broken site support issue
• [x] I've verified that I'm running youtube-dl version 2019.11.05
• [x] I've checked that all provided URLs are alive and playable in a browser
• [x] I've checked that all URLs and arguments with special characters are properly quoted or escaped
• [x] I've searched the bugtracker for similar bug reports including closed ones
• [x] I've read bugs section in FAQ

Verbose log

$ .local/bin/youtube-dl 'https://www.youtube.com/watch?v=Fmdb-KmlzD8'
[youtube] Fmdb-KmlzD8: Downloading webpage
[youtube] Fmdb-KmlzD8: Downloading video info webpage
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[download] Destination: Halo Infinite - E3 2018 - Announcement Trailer-Fmdb-KmlzD8.f399.mp4
[download] 100% of 84.85MiB in 00:09
[download] Destination: Halo Infinite - E3 2018 - Announcement Trailer-Fmdb-KmlzD8.f251.webm
[download] 100% of 2.15MiB in 00:00
[ffmpeg] Merging formats into "Halo Infinite - E3 2018 - Announcement Trailer-Fmdb-KmlzD8.mkv"
Deleting original file Halo Infinite - E3 2018 - Announcement Trailer-Fmdb-KmlzD8.f399.mp4 (pass -k to keep)
Deleting original file Halo Infinite - E3 2018 - Announcement Trailer-Fmdb-KmlzD8.f251.webm (pass -k to keep)

$ .local/bin/youtube-dl --no-continue --verbose 'https://www.youtube.com/watch?v=Fmdb-KmlzD8'
[debug] System config: []
[debug] User config: []
[debug] Custom config: []
[debug] Command-line args: ['--no-continue', '--verbose', 'https://www.youtube.com/watch?v=Fmdb-KmlzD8']
[debug] Encodings: locale UTF-8, fs utf-8, out UTF-8, pref UTF-8
[debug] youtube-dl version 2019.11.05
[debug] Python version 3.7.4 (CPython) - Linux-4.4.0-18362-Microsoft-x86_64-with-arch
[debug] exe versions: ffmpeg 4.2.1, ffprobe 4.2.1
[debug] Proxy map: {}
[youtube] Fmdb-KmlzD8: Downloading webpage
[youtube] Fmdb-KmlzD8: Downloading video info webpage
[debug] Default format spec: bestvideo+bestaudio/best
WARNING: Requested formats are incompatible for merge and will be merged into mkv.
[download] Halo Infinite - E3 2018 - Announcement Trailer-Fmdb-KmlzD8.mkv has already been downloaded and merged

Description

I would like to force overwrite an existing file, because the old one was downloaded with different quality but same file name. #5353 looks like the exact same issue. But the solution, adding --no-continue, does not work in my test.

[wangqr]

Also ref #14031 #20405

[alxnull]

I think this issue would be solved by #20405.