Comment 11 for bug 199145

I believe I may have solved my problem as kbuildsycoca4 no longer crashes, but I have yet to try logging into kde4.

I did not get output using the command above, but I did try running kbuildsycoca4 again in the terminal and I took note of all files which it claimed were not compliant with the XDG standard and which were in the ~/.local/share/applications folder. I noticed that for all of those it said they were missing a trailing semicolon in the MimeType list.

I opened all of the files it mentioned that were only in that directory, and added a semicolon to the end of the MimeType line in each. I saved all of the files and ran kbuildsycoca4 again. I still got the error with files in the folder /usr/share/applications/ but those did not seem to cause a problem. I even realized I missed one file (googleearth.desktop) which it still complained about, but no crash. Instead, it just says that it parsed those files and then it ends without problems. I will try logging into KDE4 later and will try this on a different machine as well.

This is a very strange problem which may crop up again if you change the MimeTypes of some applications, of maybe if you update one of those problematic programs' packages and they ship with "non-compliant" .desktop files.