Dear Maintainers,

First, please apologize if this bug does not belong to gnome-shell
itself.

It seems that I have a faulty EXT4 external hard drive, on which I tried
a few days ago (saturday, 12 of September) to make a backup using
Grsync: this obviously failed, so I tried to unmount the drive from
Nautilus. Of course, unmounting also failed because Grsync was still
running, and a pop-up window appeared with an error message:

Impossible to unmount "MyExternalHardDrive"
Error unmounting /dev/sdb1: Command-line `umount
"/media/yvan/MyExternalHardDrive"' exited with non-zero exit status 32:
umount: /media/yvan/MyExternalHardDrive : cible occupée
        (Dans certains cas, des renseignements sur les processus
utilisant
         le périphérique sont accessibles avec lsof(8) ou fuser(1).)

However, the problem is that a Gnome notification was displayed at the
same time saying "You can now unplug MyExternalHardDrive".

I am sorry but I can not reproduce the bug now, my external hard drive
seems to work well today.

Regards,
Yvan