Or otherwise how to attach a tarball to the release I created on gitlab. It seem to only want URL (hence the first question). All I could find on that topic is gitlab documentation that talk about token and other things, nothing about “select file” click “upload”.
To partially answer question 2 to upload to gitlab directly:
For the project you need to enable “Package Registry”. “Settings” > “General” > “Visibility, project features, permissions” and enable it there (it was off).
Create an access token with “api” permission
Then I can upload with curl (set the shell variables with the proper values):
Then “Deploy” > “Package Registry” will list the packages, and you can get the URL there to add them to the release. (the section didn’t exist priori to enabling Package Registry)