Comment 7 for bug 1664651

So the preflight/dry-run check does ensure that the name of your upload is already registered (the original description was with an older snapcraft before the functionality was added).

The preflight/dry-run has never checked whether you have permission to upload to a given existing snap name (it's not as simple as ownership). The snap push handler doesn't check this without the dry-run option either - up until now it's always been checked long after the handler returns, while processing the upload - that's where the "You do not have access to modify this package." error is being generated.

It's not impossible to move that check into the handler, but it's not as simple as checking if the name is owned by the uploader (they may be a collaborator on a related application etc.)

If I've understood correctly, a more accurate title for this bug would be "pre-flight checks do not check upload permissions for a name", and it should not affect developers uploading their own snaps, but rather only those developers who try to contribute to other snaps for which they don't yet have permission. Is that correct?