Long delay between upload finishing and form submission

[Floppy]

When files are uploaded, there seems to be a long delay (seemingly proportional to file size) before uppy accepts that the upload is done, and submits the form. I suspect Shrine is doing something in the background before saying everything is OK to go.

[Floppy]

Having looked at my raspberry pi, this is because the initial upload is going to /tmp, then is being copied to /usr/src/app/tmp before Shrine gets to look at it. And in my case, those are technically different docker filesystems, so it's copying instead of moving (hence it's fast locally). It shouldn't be doing that, surely it should go straight to the shrine tmp?

[Floppy]

This is resolved by the new tus uploader in #3384