Bug 430658

Summary:	Night Color feature stopped working on neon unstable: "Failed to connect to the Window Manager"
Product:	[Applications] systemsettings	Reporter:	Patrick Silva <bugseforuns>
Component:	kcm_nightcolor	Assignee:	Plasma Bugs List <plasma-bugs-null>
Status:	RESOLVED DOWNSTREAM
Severity:	normal	CC:	kde, kwin-bugs-null, mail, nate
Priority:	NOR	Keywords:	regression
Version First Reported In:	unspecified
Target Milestone:	---
Platform:	Neon
OS:	Linux
Latest Commit:		Version Fixed/Implemented In:
Sentry Crash Report:

Description Patrick Silva 2020-12-21 09:39:03 UTC

SUMMARY
Night Color feature is no longer working on neon unstable.
Its KCM displays "Failed to connected to the Window Manager" inline message on top.

EXPECTED RESULT
Night Color feature should work.

SOFTWARE/OS VERSIONS
Operating System: KDE neon Unstable Edition
KDE Plasma Version: 5.20.80
KDE Frameworks Version: 5.78.0
Qt Version: 5.15.2

Comment 1 Julian Steinmann 2020-12-25 18:00:37 UTC

Can reproduce, also on KDE Neon Unstable.

Comment 2 Nate Graham 2021-01-05 05:48:47 UTC

Working for me, FWIW.

Comment 3 Julian Steinmann 2021-01-05 17:10:58 UTC

Hmm. It seems as if https://invent.kde.org/plasma/kwin/-/merge_requests/530 is the relevant commit / MR. The error message comes from https://invent.kde.org/plasma/plasma-workspace/-/blob/master/libcolorcorrect/compositorcoloradaptor.cpp which tries to connect to the color correct thingy of KWin via DBus if I understood the code correctly. This path doesn't seem to exist though if I search for it within qdbusviewer.

Comment 4 David Edmundson 2021-01-05 17:26:01 UTC

It is now guarded by:

if (KWIN_BUILD_CMS)



please confirm against the build output that this dependency was found.

or check kwin debug information to confirm the plugin was loaded.

Comment 5 Julian Steinmann 2021-01-06 09:22:37 UTC

Indeed, Neon unstable built without lcms2 as a Build-Dep. I have now adjusted the build config, and the latest KWin update fixes the problem for me. @Patrick: Please reopen if against expectations the latest KWin (kwin-x11 version 4:5.20.5+p20.04+git20210106.0811-0) does not fix the problem for you.