On Kubuntu 15.10 I receive a black screen when logging in via the Display Manager. I can use Ctrl-Alt-F6 to log into a text console and see my files, but even in that environment when I type startx
the screen just goes blank and nothing further happens. I have renamed my ~/.kde
directory to ~/.kde-old
but the problem still persists.
The display manager has a setting "failsafe", when I try to log in with it set I just get booted back to the display manager screen again after a few seconds.
Here is dmesg, I've pasted what I think are the relevant lines below but clicking on the link will bring you to Pastebin where the entire log is stored.
[ 117.572448] kscreen_backend[1626]: segfault at 10 ip 00007f8c0cf068c0 sp 00007ffdfd0ed358 error 4 in KSC_XRandR.so[7f8c0cef3000+20000]
[ 118.556865] kactivitymanage[1610]: segfault at 18 ip 00007fdc57430ee0 sp 00007ffde65b6878 error 4 in libqxcb.so[7fdc57402000+b5000]
[ 118.569140] krunner[1633]: segfault at 18 ip 00007fcd52973e38 sp 00007ffed1ec3370 error 4 in libqxcb.so[7fcd5292a000+b5000]
[ 118.572032] kdeconnectd[1632]: segfault at 18 ip 00007fcb022f3e38 sp 00007ffc58549500 error 4 in libqxcb.so[7fcb022aa000+b5000]
[ 118.578476] kscreen_backend[1639]: segfault at 18 ip 00007f0956e02e38 sp 00007ffc3a121980 error 4 in libqxcb.so[7f0956db9000+b5000]
[ 118.578622] kwin_x11[1629]: segfault at 18 ip 00007f2f5d039e38 sp 00007ffcf6c160e0 error 4 in libqxcb.so[7f2f5cff0000+b5000]
[ 118.998290] plasmashell[1655]: segfault at 18 ip 00007f39a8edae38 sp 00007ffcf531f110 error 4 in libqxcb.so[7f39a8e91000+b5000]
[ 120.469171] kglobalaccel5[1685]: segfault at 18 ip 00007fc6917f1e38 sp 00007fffb2965630 error 4 in libqxcb.so[7fc6917a8000+b5000]
[ 120.475815] kglobalaccel5[1687]: segfault at 18 ip 00007f7b14409e38 sp 00007ffe5d3a59f0 error 4 in libqxcb.so[7f7b143c0000+b5000]
[ 120.735669] kglobalaccel5[1700]: segfault at 18 ip 00007fde7578ae38 sp 00007ffe9d3d7520 error 4 in libqxcb.so[7fde75741000+b5000]
[ 124.165384] show_signal_msg: 2 callbacks suppressed
[ 124.165389] korgac[1719]: segfault at 18 ip 00007f4e33530e38 sp 00007ffe1e69b010 error 4 in libqxcb.so[7f4e334e7000+b5000]
[ 124.203178] IPv6: ADDRCONF(NETDEV_UP): wlp5s0b1: link is not ready
[ 124.821375] wlp5s0b1: authenticate with b0:48:7a:fd:99:ae
[ 124.823047] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 1/3)
[ 125.023234] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 2/3)
[ 125.227080] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 3/3)
[ 125.431014] wlp5s0b1: authentication with b0:48:7a:fd:99:ae timed out
[ 125.627814] korgac[1727]: segfault at 18 ip 00007f0294472e38 sp 00007ffeec678ea0 error 4 in libqxcb.so[7f0294429000+b5000]
[ 127.951872] klauncher[1774]: segfault at 18 ip 00007f25f91b2e38 sp 00007fffc3569a90 error 4 in libqxcb.so[7f25f9169000+b5000]
[ 136.059194] wlp5s0b1: authenticate with b0:48:7a:fd:99:ae
[ 136.059317] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 1/3)
[ 136.261035] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 2/3)
[ 136.464894] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 3/3)
[ 136.668804] wlp5s0b1: authentication with b0:48:7a:fd:99:ae timed out
[ 149.191322] IPv6: ADDRCONF(NETDEV_UP): wlp5s0b1: link is not ready
[ 149.816413] wlp5s0b1: authenticate with b0:48:7a:fd:99:ae
[ 149.816517] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 1/3)
[ 150.017451] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 2/3)
[ 150.221322] wlp5s0b1: direct probe to b0:48:7a:fd:99:ae (try 3/3)
[ 150.425210] wlp5s0b1: authentication with b0:48:7a:fd:99:ae timed out
[ 152.779659] kscreen_backend[1965]: segfault at 10 ip 00007f253f78c8c0 sp 00007ffe7a87d1b8 error 4 in KSC_XRandR.so[7f253f779000+20000]
[ 152.941924] kactivitymanage[1952]: segfault at 18 ip 00007f1ae218bee0 sp 00007ffe18581458 error 4 in libqxcb.so[7f1ae215d000+b5000]
[ 152.973211] kscreen_backend[1976]: segfault at 18 ip 00007f6ec2cf9e38 sp 00007ffe34ea0320 error 4 in libqxcb.so[7f6ec2cb0000+b5000]
[ 152.997937] ksmserver[1975]: segfault at 18 ip 00007f756b05de38 sp 00007fffb2c7fe80 error 4 in libqxcb.so[7f756b014000+b5000]
I was unable to find where xrandr
stores it's configuration and the X log doesn't seem to have anything amiss. How should I troubleshoot from here, short of nuking ~
or even /
?
Note that this Kubuntu version uses Plasma 5, so I did a new install and not an upgrade from the previous version. The install went well, I've been using the system without any related problems for over a week now. This is a laptop computer that sometimes is connected to an external monitor.
EDIT: I just created a new user test
, which also gets booted out of the supposed fail safe login mode. However, this user can log into its desktop just fine. Therefore the problem seems to be in a config file of my user. I'm currently bisecting them now, but I'm still open to ideas. Thank you.