Update 7/15/2020: See #381 (comment) for a roadmap

I was trying to debug twine usage (and especially twine upload) and making it more verbose but apparently there is no documentation about any verbose mode.

Even if I found some references in the source code to a --verbose option, apparently this is not recognised by twine.

Please advise how to enable a more verbose mode on twine so we would know what went wrong when we got an error like #289 (comment)