Clipboard monitoring fails when main window closed and QT_QPA_PLATFORM=xcb on Wayland (“Qt: Session management error: Could not open network socket”)

[robertstrom]

Describe the bug
When I copy something and then copy a second something and then open CopyQ, only the second something that I copied is there saved in CopyQ. I thought that I had found the solution when I found a discussion that seemed to be talking about the same issue. That discussion said to install the Reset Empty Clipboard command. I have installed that command and exited CopyQ and restarted CopyQ and the behavior is still the same.

To Reproduce
Already explained above - CopyQ item 1 to the clipboard. Do not open CopyQ. Copy item 2 to clipboard, then open CopyQ. Only item 2 will be stored. Item #1 is not to be found.

Expected behavior
When I copy multiple things in a row all of the things that I have copied are stored in CopyQ without me having to open the CopyQ program after copying each item.

How can I get CopyQ to work like it always has on an X11 DE where I can copy 10 (or however many) items in a row and they will all be stored in CopyQ?

Screenshots

Version, OS and Environment

CopyQ 15.0.0
Arch: x86_64-little_endian-lp64
Audio: miniaudio 0.11.25
Compiler: GCC
DISPLAY: :1
KGuiAddons: 6.25.0
KNotifications: 6.25.0
KStatusNotifierItem: 6.25.0
OS: CachyOS
QCA: 2.3.10
Qt: 6.11.0
QtKeychain: 0.15.0
WAYLAND_DISPLAY: wayland-1
XDG_CURRENT_DESKTOP: COSMIC
XDG_SESSION_DESKTOP: COSMIC
XDG_SESSION_TYPE: wayland
has-audio: 1
has-encryption: 1
has-global-shortcuts: 1
has-keychain: 1
has-mouse-selection: 1

Additional context

I am starting CopyQ using the recommended method for a Wayland DE. The auto start is set in the Cosmic DE, not by checking the AutoStart box in CopyQ itself. The /usr/share/applications/com.github.hluk.copyq.desktop launcher uses the command shown below.

Exec=env QT_QPA_PLATFORM=xcb copyq

If I start CopyQ manually from the command line I run

env QT_QPA_PLATFORM=xcb copyq &

logs

[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:16:59.096] Note <Server-15955>: Exporting settings
[2026-05-01 08:16:59.098] Note <Server-15955>: Exporting commands
[2026-05-01 08:16:59.158] Note <cmd/onExit-74483>: Terminating application on signal 15
[2026-05-01 08:17:00.767] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:17:00.778] Note <Server-15955>: Terminating application on signal 15
[2026-05-01 08:17:00.779] Warning <Server-15955>: Command “copyq onExit”: Exit code: 143 | 1. copyq onExit
[2026-05-01 08:17:00.779] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:17:00.949] Warning <Server-15955>: [default] The X11 connection broke (error 1). Did the X11 server die?
[2026-05-01 08:36:29.488] Note <Server-5917>: Starting server: CopyQ 15.0.0
[2026-05-01 09:19:50.617] Warning <cmd/monitorClipboard-5927>: Aborting clipboard cloning: Clipboard changed again
[2026-05-01 09:25:39.739] Warning <cmd/monitorClipboard-5927>: Aborting clipboard cloning: Clipboard changed again
[2026-05-01 12:56:29.428] Warning <cmd/monitorClipboard-5927>: Aborting clipboard cloning: Clipboard changed again
[2026-05-03 12:55:49.420] Note <Server-5917>: Exporting settings
[2026-05-03 12:55:49.423] Note <Server-5917>: Exporting commands
[2026-05-03 12:55:56.288] Note <Server-63522>: Starting server: CopyQ 15.0.0
[2026-05-03 19:15:44.444] Note <Server-63522>: Exporting settings
[2026-05-03 19:15:44.445] Note <Server-63522>: Exporting commands
[2026-05-03 19:15:44.952] ERROR <cmd/onClipboardChanged-88279>: Cannot connect to server! Start CopyQ server first.
[2026-05-03 19:16:17.003] Note <Server-88334>: Starting server: CopyQ 15.0.0

[robertstrom]

After posting this I had a little chat with Google Gemini and I may have found the solution. I have done a bit of testing and I have also rebooted after making the change to the CopyQ launcher and it seems to be saving all of the things that I am copying.

This is the command line that was suggested by Google Gemini and it does appear to be, with some basic testing done, working

Exec=env QT_QPA_PLATFORM=wayland QT_WAYLAND_DISABLE_WINDOWDECORATION=1 copyq

Any thoughts / comments about the issue that I have been experiencing and the new command line to launch?

These are the logs since restarting

[2026-05-03 19:43:23.311] Note <Server-90038>: Starting server: CopyQ 15.0.0
[2026-05-03 19:47:10.479] Note <Server-90038>: Exporting settings
[2026-05-03 19:47:10.486] Note <Server-90038>: Exporting commands
[2026-05-03 19:48:29.767] Note <Server-91299>: Starting server: CopyQ 15.0.0
[2026-05-03 19:49:43.549] Note <Server-91299>: Exporting settings
[2026-05-03 19:49:43.559] Note <Server-91299>: Exporting commands
[2026-05-03 19:49:50.452] Note <Server-91464>: Starting server: CopyQ 15.0.0
[2026-05-03 19:51:06.859] Note <Server-91464>: Exporting settings
[2026-05-03 19:51:06.866] Note <Server-91464>: Exporting commands
[2026-05-03 19:51:11.311] Note <Server-91987>: Starting server: CopyQ 15.0.0
[2026-05-03 19:52:47.335] Warning <Server-91987>: [default] The Wayland connection broke. Did the Wayland compositor die?
[2026-05-03 19:52:47.336] Warning <cmd/synchronizeToSelection-92025>: [default] The Wayland connection broke. Did the Wayland compositor die?
[2026-05-03 19:52:47.337] Warning <cmd/synchronizeFromSelection-92192>: [default] The Wayland connection broke. Did the Wayland compositor die?
[2026-05-03 19:52:47.338] Warning <cmd/monitorClipboard-91999>: [default] The Wayland connection broke. Did the Wayland compositor die?
[2026-05-03 19:52:47.355] ERROR <Client-92004>: Connection lost!
[2026-05-03 19:53:52.480] Note <Server-1326>: Starting server: CopyQ 15.0.0
[2026-05-03 19:53:53.590] Warning <Server-1326>: [qt.qpa.services] Failed to register with host portal QDBusError("org.freedesktop.portal.Error.Failed", "Could not register app ID: Connection already associated with an application ID")
[2026-05-03 19:53:53.591] Warning <cmd/monitorClipboard-1555>: [qt.qpa.services] Failed to register with host portal QDBusError("org.freedesktop.portal.Error.Failed", "Could not register app ID: App info not found for ''")

[Chealer]

@robertstrom: Please provide reproduction steps in the form of a numbered list of clear steps. For example, "Open CopyQ" is vague―do you mean opening the main window?

If you think this is specific to Wayland, please reflect that in the ticket's title.

[robertstrom]

@Chealer - I updated the title to include the fact that this is a probable Wayland issue.

Here are the steps to reproduce the issue that I have been seeing.

If I have the CopyQ launcher set to use this Exec= line

Exec=env QT_QPA_PLATFORM=xcb copyq

and then:

• Copy text line 1
• Copy text line 2
• Copy text line 3

Then look at CopyQ by clicking on the CopyQ icon in the tray to open the CopyQ application, only Copy text line 3 will be stored in CopyQ

If I:

• Copy text line 1
• Open CopyQ the same way as described above
• I will see Copy text line 1
• Copy text line 2
• Open CopyQ the same way as described above
• I will see Copy text line 2
• Copy text line 3
• Open CopyQ the same way as described above
• I will see Copy text line 3

If I change the Exec= line to be

Exec=env QT_QPA_PLATFORM=wayland QT_WAYLAND_DISABLE_WINDOWDECORATION=1 copyq

• Close out of the CopyQ program

• Restart CopyQ by pressing the Super key and selecting the CopyQ launcher (which is now using the modified Exec= command)

• and then:

• Copy text line 1

• Copy text line 2

• Copy text line 3

I will see all of the three lines that I copied without having to open CopyQ in between each line (or section of text copied)

Hopefully I have included enough of a step by step description of the issue that I am seeing.

Please let me know if you need any additional information.

Thanks!

[robertstrom]

@Chealer - Any update on this?

[Chealer]

@robertstrom: What I meant by a numbered list of clear steps is one where each item starts with incremental integers, like the following:

1. Start CopyQ
2. Close the main window if it is open.
3. Select “Dummy 1“ and copy it
4. Select “Dummy 2“ and copy it
5. Select “Dummy 3“ and copy it

Using the above sequence, I can reproduce this using the Flatpak package on Debian 13:
CopyQ 15.0.0
Arch: x86_64-little_endian-lp64
Compiler: GCC
DISPLAY: :1
KGuiAddons: 6.24.0
KNotifications: 6.24.0
KStatusNotifierItem: 6.24.0
OS: KDE Flatpak runtime
Qt: 6.10.2
WAYLAND_DISPLAY: wayland-0
XDG_CURRENT_DESKTOP: KDE
XDG_SESSION_DESKTOP: KDE
XDG_SESSION_TYPE: wayland

However, this only reproduces for some CopyQ launches. It seems that a launch is affected if and only if it writes the following on startup to the console:

Warning: [default] Qt: Session management error: Could not open network socket

I have not been able to trigger that warning/bug when launching with:

$ /usr/bin/flatpak run --command=copyq com.github.hluk.copyq

However, I can apparently reproduce reliably when launching with:

$ QT_QPA_PLATFORM=xcb /usr/bin/flatpak run --command=copyq com.github.hluk.copyq

Please retitle this to something like:

Clipboard monitoring fails when main window closed and QT_QPA_PLATFORM=xcb on Wayland (“Qt: Session management error: Could not open network socket”)

🅭🄍

[robertstrom]

@Chealer

Please retitle this to something like:

Clipboard monitoring fails when main window closed and QT_QPA_PLATFORM=xcb on Wayland (“Qt: Session management error: Could not open network socket”)

Done

It's possible that some of the behavior is Cosmic DE specific or the combination of CachyOS and the Cosmic DE

[Chealer]

Thank you Robert

It's possible that some of the behavior is Cosmic DE specific or the combination of CachyOS and the Cosmic DE

I am not sure what you mean by "some of the behavior". I read this whole ticket as reporting a single specific misbehavior, and that bug affects KDE when running on Debian. The message “Qt: Session management error: Could not open network socket” suggests this could be just 1 symptom of a root bug causing more symptoms, though.

[hluk]

This looks like a problem with XWayland on Cosmic DE.

The recommended way to run CopyQ is natively under Wayland compositors, and use the QT_QPA_PLATFORM=xcb only if clipboard monitoring does not work or the Wayland Support command did not help to fix other required functionality.

I'm updating the documentation about Wayland: #3603