Dolphin Cannot mount external encrypted hard drive

Help
1 
NixOS 23.11
Wayland
Plasma & Sway
Dolphin
LUKS encryption

When I use Dolphin in Plasma (startplasma-wayland) I can mount an encrypted external hard drive by clicking on the drive name in the left sidebar. A dialog window pops up asking for the password:
KDEdaemon

But when I use Dolphin in Sway, the dialog window does not appear.
Starting Dolphin in the Konsole reveals the following error:

libpng warning: iCCP: known incorrect sRGB profile
kf.solid.backends.udisks2: Failed to call the SolidUiServer, D-Bus said:
 QDBusError("org.freedesktop.DBus.Error.UnknownObject", "No such object path '/modules/soliduiserver'")

Does anybody know what to do?

2

I don’t really know what to do about this, sadly, the only thing I found is that someone on reddit two years ago having the same issue (with an encrypted drive, same error message), and it appears to have been reported to kde developers.

Unless someone else with more insight into this than me comes along, you might want to try another file manager for use with Sway.

3

Using Plasma-Wayland, Dolphin can mount LUKS drives.
So, I guess it may be related to Sway and KDE Password Daemon.

Which file manager can mount LUKS drives in Sway?

4

Which file manager can mount LUKS drives in Sway?

Yes, that is a good question. Thunar cannot do it? I am not sure, I am neither using KDE or anything like Sway at the moment.

5

I encountered the exact same problem using dolphin in gnome(yes, gnome). After searching for a while I found that the SolidUiServer is a part of plasma-workspace. Finally I fixed this issue by installing plasma-workspace and I can now happily drop nautilus.

6

Thanks for your hint.
I installed explicitly libsForQt5.plasma-workspace but that did not help.
I say explicitly because I assume that it has been installed already via the installation of KDE/Plasma.
I have both installed: KDE and sway.

7

I have installed the following packages:

libsForQt5.dolphin
libsForQt5.konsole
libsForQt5.qt5ct
libsForQt5.plasma-workspace
libsForQt5.kded

And dolphin can normally ask the disk pass in gnome. Maybe kded?

8

It looks like soliduiserver is a component of Plasma, and it looks like that udisks plugin is looking for it over dbus to do passphrase entry. You can probably normally mount it with another udisks interface. Maybe there’s another mounting backend, or a way to ask the mounting backend to use something other than soliduiserver, I’m not sure.

9

Thanks for your reply.
So I guess soliduiserver is started only, when Plasma is started but not when I use sway.