Bug 293536

I have the same issue with kde-4.8.0 .xsession-errors during login with enabled  or disabled nepomuk. 
It seems for this reason plasma-desktop start slow and login takes about 30 seconds (amd phenom II X4 3.2 Ghz, HDD WDC WD4000AAKS-0) as errors write at the same time.

P.S. 
Moving /var/tmp/kdecache-<user> to tmpfs doesn't make startup faster and something is handling of HDD on logon.

I has made some test:

testcase A (Nepomuk disabled before KDE start)
1. KDE starts (after reboot) with disable nepomuk the errors messages this bug reports bigin to spam .xsesion-errrors file 
2. I opened systemsettings and Enable Nepomuk Semantic Desktop (without File Indexing and without Email Indexer), Press "Enable" button
3. After Akonadi and Nepomuk starting "kactivitymanagerd" stops spam to logfile (or just  sometimes crashed like in "testcase B", but not necessarily)
See attached file "xsession-errors_nepomuk_starting.log"


testcase B (Nepomuk enabled before KDE start)
1. "kactivitymanagerd" write to .xsesion-errrors file about error during KDE startup but crashes later when Nepomuk on loading.
See full attached file "xsession-errors_nepomuk_on_kde_start.log"

Created attachment 68702 [details]
Nepomuk is disabled before KDE start/logon and is "Enabled" with Systemsettings

Created attachment 68703 [details]
Nepomuk is Enabled before Reboot and "kactivitymanagerd" sometimes crashes during Nepomuk starting

confirmed - activating Nepomuk and disabling file and email indexing helped.

But I don't want Nepomuk enabled at al :-(

But even with "kactivitymanagerd" error mesasage take plase before nepomuk services starting (especialy during logon - It may need to check it one more time, but if it has place - it may cause the slow kde login) - and "kactivitymanagerd" crashes almost all the time with nepomuk enabled.

I use "semantic-desktop" compiling option (in Gentoo) just for KMail (currently for 4.4.11.1 due to many bugs of Akonadi services that corrupted KMail2)

Some users install KDE without "semantic-desktop" compiling option - so permanent loging of "kactivitymanagerd" errors is a bug in itself.

To me it is still not clear who's "fault" it is. Should this bug be assigned to Soprano? KMail? Plasma activities?

Kmail doesn't concern this bug (it was just referenced as application that need "semantic-desctop" feature).

Most likely it's a bug of "kactivitymanagerd" (maybe it tries to use Soprano for some purpose) component of "kactivities" packet that spam to .xsession-error file until nepomuk is started and crashes sometimes during nepomuk's startup (see attached log files for details).

*** Bug 293806 has been marked as a duplicate of this bug. ***

Confirmed by duplicates.

*** Bug 293898 has been marked as a duplicate of this bug. ***

Argh, how I love typos of important search keywords ... sorry for the spam.

*** Bug 294519 has been marked as a duplicate of this bug. ***

*** Bug 294834 has been marked as a duplicate of this bug. ***

Yeah, kactivitymanagerd should stop trying to use Nepomuk if it is explicitly disabled.

I believe the bug is with Soprano or Nepomuk. I had the same errors as reported above, killed kactivitymanager and now am getting spammed with the exact same messages only now from kfilemetareader. 

Before killing kactivitymanager
The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
QObject: Cannot create children for a parent that is in a different thread.
(Parent is Soprano::Client::LocalSocketClient(0xa3e5e8), parent's thread is QThread(0x8bb330), current thread is RankingsUpdateThread(0xaa76b0)
"/usr/bin/kactivitymanagerd(2146)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/usr/bin/kactivitymanagerd(2146)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/usr/bin/kactivitymanagerd(2146)" Soprano: "Unsupported operation (2)": "Invalid model"
"/usr/bin/kactivitymanagerd(2146)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/usr/bin/kactivitymanagerd(2146)" Soprano: "Unsupported operation (2)": "Invalid model"
"/usr/bin/kactivitymanagerd(2146)" Soprano: "Invalid iterator."

After killing kactivitymanager
The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/usr/bin/kfilemetadatareader(23749)" Soprano: "QLocalSocket::connectToServer: Invalid name"
"/usr/bin/kfilemetadatareader(23749)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/usr/bin/kfilemetadatareader(23749)" Soprano: "Unsupported operation (2)": "Invalid model"
"/usr/bin/kfilemetadatareader(23749)" Soprano: "org.freedesktop.DBus.Error.ServiceUnknown - The name org.kde.nepomuk.services.nepomukstorage was not provided by any .service files"
"/usr/bin/kfilemetadatareader(23749)" Soprano: "Unsupported operation (2)": "Invalid model"
"/usr/bin/kfilemetadatareader(23749)" Soprano: "Invalid iterator."

This can be considered a problem of both nepomuk and users of it. It should be fixed in one place or another. Currently, fixed in KAMD :)

(In reply to comment #17)
> This can be considered a problem of both nepomuk and users of it. It should
> be fixed in one place or another. Currently, fixed in KAMD :)
Any chance for a 4.8.1 useer to back port this by giving a link to the diff/patch ?