Alexander Gromnitsky's Blog

fusermount3 & Dolphin

Latest update: 2023-07-16 21:14:54

I tried to run KDE Dolphin outside of a running KDE Plasma instance (i.e., from fvwm3) & found I'm unable to copy files with it.

This is so linux (apart form an error message, where a d-bus reply is injected in the place of a file name): you install a file manager that does all the fancy stuff: thumbnails rendering, usb device mounting, running an associated program when you hit Return on a file name, but no file management. Why would anyone want to copy a file using a file manager? Are you 5 years old? Use rsync, dummkopf.

Googling helped very little. There is a bug report, where a guy with Gentoo (good grief) had a similar issue that he resolved via installing the fuse kernel module. This didn't apply to me, for Fedora 38 already comes with a working fuse support, but when I run "journalctl -b -f --user" I saw

Jul 16 18:49:39 a520 org.freedesktop.portal.Documents[10175]: fusermount3: failed to access mountpoint /run/user/1000/doc: Permission denied
Jul 16 18:49:39 a520 org.freedesktop.portal.Documents[10168]: error: fuse init failed: Can't mount path /run/user/1000/doc

when Dolphin was trying to move a file.

This time I was dumbstruck, until I checked the value of DBUS_SESSION_BUS_ADDRESS env var. I was launching fvwm3 from ~/.xinitrc like so, which is apparently wrong?

exec dbus-launch --exit-with-session fvwm3

I changed it to

export DBUS_SESSION_BUS_ADDRESS=unix:path=/run/user/$UID/bus
fvwm3

& boom! Voilà! Suddenly, I had no errors during the xdg-document-portal.service activation.

For posterity, this is a list of the relevant installed packages I need to run Dolphin successfully:

$ rpm -qa --queryformat '%{name}\n' 'xdg|gvfs*' | sort
gvfs
gvfs-client
gvfs-fuse
gvfs-gphoto2
gvfs-mtp
xdg-dbus-proxy
xdg-desktop-portal
xdg-desktop-portal-gtk
xdg-user-dirs
xdg-user-dirs-gtk
xdg-utils