Nice! I updated the branch to be in sync with the refactoring of the logic of image validation and error messages. Can you have a quick look again, if this is in your sense. Then I merge it :)

Uh, your commit broke it. I will investigate.
PS : I was not aware of this other PR, I like it!

Uh, your commit broke it. I will investigate.

Ah sorry for breaking it... I guess I know what went wrong: it should return dict() and not dict. I missed to add this correctly...

I looked at it. The problem comes from the fact that the first instruction of image_works_with_device() is calling retrieve_image_metadata() : it tries to find metadata, then fails in the case it's not a zip file.
It's written in the logs, but there is no way to send this information to the first called function : then, the showed message is the same as a file without metadata (because the second function only send an empty dictionary)... But it shouldn't.

How do we handle that?

I tried to handle it, now it should work smoothly.

Let me know what you think :)

Yes, it works, !