Regression: cp fails to copy files to Android device using MTP (os error 95)

[Ethran]

OS: Ubuntu 25.10 beta (all updates as of September 23rd)

Problem:
Copying files to an Android device via MTP fails with the Rust coreutils cp command. After connecting an Android device via USB (MTP mode) and running:

cp 'main.pdf' '/run/user/1000/gvfs/mtp:host=QUALCOMM_LAGOON-MTP__SN%3AEC8FEFA4_9c03b7ab/Internal shared storage/Documents/main.pdf'

I get the error:

cp: 'main.pdf' -> '/run/user/1000/gvfs/mtp:host=QUALCOMM_LAGOON-MTP__SN%3AEC8FEFA4_9c03b7ab/Internal shared storage/Documents/main.pdf': Operation not supported (os error 95)

With GNU coreutils, the copy operation succeeds.

[paneutral]

mv has the same problem. The annoying thing is that it creates an empty file that it doesn't clean up after it fails. This is a problem in itself, it should clean up the destination.

The reason for this problem is that MTP isn't a real file system and doesn't support modes, ownership, etc. When it tries to write the source metadata to the destination, it fails. GNU mv copies the file first and then fails while set the metadata, which is then gone forever I guess.