KDE Plasma Wayland can't log in. kickback to login screen

Big Scorpio · 2026-04-03 18:25:56

Hello Arch Friends,

Another day, another Linux problem showing up out of literally nowhere and having done nothing systematically for it to happen.
I'm using SDDM and KDE Plasma Wayland to log in. After entering my password and hitting enter, the screen goes black with a white underscore on the upper left corner of the screen and a few seconds later I am kicked back at the login screen.
Doesn't happen with Plasma X11.

Here is what I've tried:

renaming ~.config to .config_old
sudo pacman -Syu

Still nothing.
JournalCTL has been recorded here as i've made multiple "successfully failed" login attempts and then logged it via alternative display terminal.
Since 0x0.st shows me this

uploads disabled because it’s been almost nothing but AI botnet spam for the past few months. will be back with a few changes at some point. no ETA.

and many other file/pastebin sharing services are being nothing but a pain in the A, i'll have to upload my journalctl elsewhere -> https://drive.proton.me/urls/25N0QRNSF0#WzJPKYyArnk8

Password is "ArchLinux"

What can be done to fix this?

Big Scorpio · 2026-04-04 17:35:26

Note: This problem might be a side effect of https://bbs.archlinux.org/viewtopic.php?pid=2293384 that I am having. Working on solving that first.

seth · 2026-04-04 20:11:56

sudo journalctl -b | nc termbin.com 9999

Crashes all over the place

sudo LC_ALL=C pacman -Qkk | grep -v ', 0 altered files' | grep -v backup
pacman -Qs nvidia # some glx issues specifically and you're using the 580xx drivers

Big Scorpio · 2026-04-05 14:35:43

https://termbin.com/16plg

[motherfucker_big_scorpio@Nexus ~]$ sudo LC_ALL=C pacman -Qkk | grep -v ', 0 altered files' | grep -v backup
warning: cups: /etc/cups/classes.conf (Permissions mismatch)
warning: cups: /etc/cups/printers.conf (Permissions mismatch)
warning: cups: /etc/cups/subscriptions.conf (Permissions mismatch)
warning: java-runtime-common: /usr/lib/jvm/default (Symlink path mismatch)
warning: java-runtime-common: /usr/lib/jvm/default (Modification time mismatch)
warning: java-runtime-common: /usr/lib/jvm/default-runtime (Symlink path mismatch)
warning: java-runtime-common: /usr/lib/jvm/default-runtime (Modification time mismatch)
warning: libcmrt: /usr/lib/libcmrt.so (Permissions mismatch)
warning: libcmrt: /usr/lib/libcmrt.so.1 (Permissions mismatch)
warning: libutempter: /usr/lib/utempter/utempter (GID mismatch)
warning: libutempter: /usr/lib/utempter/utempter (Permissions mismatch)
warning: libvlc: /usr/lib/vlc/plugins/plugins.dat (Modification time mismatch)
warning: libvlc: /usr/lib/vlc/plugins/plugins.dat (Size mismatch)
warning: libvlc: /usr/lib/vlc/plugins/plugins.dat (SHA256 checksum mismatch)
cups: 947 total files, 3 altered files
java-runtime-common: 21 total files, 2 altered files
libcmrt: 16 total files, 2 altered files
libutempter: 20 total files, 1 altered file
libvlc: 120 total files, 1 altered file
warning: shadow: /usr/bin/groupmems (GID mismatch)
warning: shadow: /usr/bin/groupmems (Permissions mismatch)
warning: systemd: /var/log/journal (GID mismatch)
warning: wireguard-tools: /etc/wireguard (Permissions mismatch)
shadow: 576 total files, 1 altered file
systemd: 1826 total files, 1 altered file
wireguard-tools: 99 total files, 1 altered file
[motherfucker_big_scorpio@Nexus ~]$ 

[motherfucker_big_scorpio@Nexus ~]$ pacman -Qs nvidia
local/cuda 13.2.0-1
    NVIDIA's GPU programming toolkit
local/egl-gbm 1.1.3-1
    The GBM EGL external platform library
local/egl-wayland 4:1.1.21-1
    EGLStream-based Wayland external platform
local/egl-x11 1.0.5-1
    NVIDIA XLib and XCB EGL Platform Library
local/lib32-nvidia-580xx-utils 580.142-1
    NVIDIA drivers utilities (32-bit) (580xx)
local/libva-nvidia-driver 0.0.16-1
    VA-API implementation that uses NVDEC as a backend
local/libvdpau 1.5-4
    Nvidia VDPAU library
local/libxnvctrl-580xx 580.142-1
    NVIDIA NV-CONTROL X extension (580xx)
local/linux-firmware-nvidia 20260309-1
    Firmware files for Linux - Firmware for NVIDIA GPUs and SoCs
local/nvidia-580xx-dkms 580.142-2
    NVIDIA kernel modules - module sources (580xx)
local/nvidia-580xx-settings 580.142-1
    Tool for configuring the NVIDIA graphics driver (580xx)
local/nvidia-580xx-settings-debug 580.142-1
    Detached debugging symbols for nvidia-580xx-settings
local/nvidia-580xx-utils 580.142-2
    NVIDIA drivers utilities (580xx)
local/nvtop 3.3.2-1
    GPUs process monitoring for AMD, Intel and NVIDIA
local/opencl-nvidia-580xx 580.142-2
    OpenCL implemention for NVIDIA (580xx)
[motherfucker_big_scorpio@Nexus ~]$

And now?

seth · 2026-04-05 17:36:04

You don't seem to have overly suspicious package deviations (and the nvidia packages are also version aligned)
The crashes seem to come from https://man.archlinux.org/man/fnmatch.3 and https://man.archlinux.org/man/regcomp.3

pacman -Qikk glibc

Big Scorpio · 2026-04-06 15:57:10

[motherfucker_big_scorpio@Nexus ~]$ sudo pacman -Qikk glibc
Name            : glibc
Version         : 2.43+r5+g856c426a7534-1
Description     : GNU C Library
Architecture    : x86_64
URL             : https://www.gnu.org/software/libc
Licenses        : GPL-2.0-or-later  LGPL-2.1-or-later
Groups          : None
Provides        : None
Depends On      : linux-api-headers>=4.10  tzdata  filesystem
Optional Deps   : gd: for memusagestat [installed]
                  perl: for mtrace [installed]
Required By     : 7zip  a52dec  abseil-cpp  accounts-qml-module  accountsservice  acl  ada  aha  alsa-lib  alsa-plugins  aom  appstream  appstream-qt  argon2  at-spi2-core  attica  attr  audacity  audit
                  aurorae  avahi  baloo  baloo-widgets  base  bash  binutils  bison  blas  bluedevil  bluez  bluez-libs  bluez-qt  boost-libs  breeze  breeze-icons  breeze-plymouth  brotli  bubblewrap  bzip2
                  c-ares  cabextract  cairo  cairomm  cairomm-1.16  cbindgen  cblas  cdparanoia  ceserver  cinnamon  cinnamon-control-center  cinnamon-desktop  cinnamon-screensaver  cinnamon-session
                  cinnamon-settings-daemon  cjs  clucene  colord  compiler-rt  composefs  convertlit  coreutils  cryptsetup  cups  cups-filters  dav1d  dbus  dbus-broker  dbus-glib  dconf  ddcutil  debugedit
                  desktop-file-utils  device-mapper  diffutils  discount  discover  dmidecode  dolphin  dosfstools  double-conversion  drkonqi  duktape  dump_syms  ebook-tools  editorconfig-core-c  efibootmgr
                  efivar  egl-gbm  egl-wayland  egl-x11  electron34  electron36  electron37  elfutils  enchant  evolution-data-server  exempi  exiv2  expat  faad2  fakeroot  fatresize  ffmpeg  ffmpeg4.4  fftw
                  file  findutils  firefox  flac  flatpak  flatpak-kcm  flex  fontconfig  frameworkintegration  freeglut  freerdp  freetype2  fribidi  fuse2  fuse3  gamemode  gawk  gcc-libs  gcc13-libs
                  gcc14-libs  gcr  gcr-4  gdb  gdbm  gdk-pixbuf2  geocode-glib-2  gettext  ghostscript  giflib  glib-networking  glib2  glibmm  glibmm-2.68  glslang  glu  glycin  gmp  gnome-color-manager
                  gnome-desktop  gnome-desktop-4  gnu-netcat  gnupg  gnutls  gocryptfs  goocanvas  gperftools  gpgme  gpgmepp  graphene  graphite  grep  groff  grub-customizer  gsm  gsound  gssdp
                  gst-plugins-bad-libs  gst-plugins-base  gst-plugins-base-libs  gstreamer  gtest  gtk-update-icon-cache  gtk3  gtk4  gtkmm-4.0  gtkmm3  gupnp  gupnp-igd  gvfs  gzip  harfbuzz  harfbuzz-icu
                  highway  hunspell  hwloc  hyphen  icu  iio-sensor-proxy  ijs  imagemagick  imake  imath  inetutils  intel-gmmlib  intel-media-driver  intel-media-sdk  ipp-usb  iproute2  jansson  jasper
                  jbig2dec  jbigkit  jdk-openjdk  jq  js115  js128  json-c  json-glib  kaccounts-integration  kactivitymanagerd  karchive  kate  kauth  kbd  kbookmarks  kcmutils  kcodecs  kcolorscheme
                  kcompletion  kconfig  kconfigwidgets  kcoreaddons  kcrash  kdbusaddons  kde-cli-tools  kde-gtk-config  kdeclarative  kdecoration  kded  kdeplasma-addons  kdesu  kdnssd  kdsoap
                  kdsoap-ws-discovery-client  keyutils  kfilemetadata  kgamma  kglobalaccel  kglobalacceld  kguiaddons  kholidays  ki18n  kiconthemes  kidletime  kimageformats  kinfocenter  kio  kio-extras
                  kio-fuse  kirigami  kirigami-addons  kitemmodels  kitemviews  kjobwidgets  kmenuedit  kmod  knewstuff  knighttime  knotifications  knotifyconfig  konsole  kpackage  kparts  kpipewire  kpty
                  kquickcharts  kquickimageeditor  krb5  krdp  krunner  ksanecore  kscreen  kscreenlocker  kservice  ksshaskpass  kstatusnotifieritem  ksvg  ksystemstats  ktexteditor  ktextwidgets
                  kunitconversion  kuserfeedback  kwallet  kwallet-pam  kwayland  kwidgetsaddons  kwin  kwin-x11  kwindowsystem  kwrited  kxmlgui  l-smash  lame  lapack  layer-shell-qt  leancrypto
                  lib32-glibc  libabw  libaccounts-glib  libaccounts-qt  libadwaita  libaio  libappindicator  libarchive  libasan  libass  libassuan  libasyncns  libatasmart  libatomic  libatomic_ops
                  libavc1394  libavif  libb2  libblockdev  libblockdev-crypto  libblockdev-fs  libblockdev-loop  libblockdev-mdraid  libblockdev-nvme  libblockdev-part  libblockdev-smart  libblockdev-swap
                  libbluray  libbpf  libbs2b  libbsd  libbytesize  libcap  libcap-ng  libcdio  libcdio-paranoia  libcdr  libcloudproviders  libcmis  libcolord  libcups  libcupsfilters  libdaemon
                  libdatachannel  libdatrie  libdbusmenu-glib  libdbusmenu-gtk3  libdc1394  libdca  libde265  libdeflate  libdisplay-info  libdmtx  libdovi  libdrm  libdvbpsi  libdvdnav  libdvdread  libe-book
                  libebur128  libedit  libei  libelf  libepoxy  libepubgen  libetonyek  libevdev  libevent  libexif  libexttextcat  libfdk-aac  libffi  libfm-extra  libfontenc  libfreeaptx  libfreehand
                  libfyaml  libgcc  libgcrypt  libgee  libgfortran  libgirepository  libgnomekbd  libgoa  libgomp  libgpg-error  libgphoto2  libgtop  libgudev  libgweather-4  libheif  libical  libice
                  libid3tag  libidn  libieee1284  libimobiledevice  libimobiledevice-glue  libinih  libinput  libixion  libjpeg-turbo  libjuice  libjxl  libkexiv2  libksane  libksba  libkscreen  libksysguard
                  liblangtag  liblc3  libldac  libliftoff  liblqr  liblsan  libmad  libmalcontent  libmanette  libmbim  libmd  libmfx  libmm-glib  libmng  libmnl  libmodplug  libmpc  libmpcdec  libmpeg2
                  libmspack  libmspub  libmtp  libmwaw  libndp  libnet  libnewt  libnfnetlink  libnghttp2  libnghttp3  libngtcp2  libnice  libnl  libnm  libnotify  libnsl  libnumbertext  libnvme  libobjc
                  libodfgen  libogg  libopenmpt  liborcus  libp11-kit  libpagemaker  libpaper  libpcap  libpciaccess  libpgm  libphonenumber  libpipewire  libplacebo  libplasma  libplist  libppd  libproxy
                  libpulse  libqaccessibilityclient-qt6  libqalculate  libqmi  libqrtr-glib  libquadmath  libqxp  libraqm  libraw1394  libreoffice-fresh  librevenge  librsvg  libsamplerate  libsasl  libsbsms
                  libseccomp  libsecret  libsfdo  libsigc++  libsigc++-3.0  libsixel  libsm  libsndfile  libsodium  libsoup  libsoup3  libsrtp  libssc  libssh  libstaroffice  libstdc++  libstemmer  libtasn1
                  libtatsu  libteam  libthai  libtheora  libtiff  libtirpc  libtommath  libtool  libtsan  libubsan  libunibreak  libunistring  libunwind  libupnp  libusb  libusbmuxd  libutempter  libuv
                  libva-nvidia-driver  libvdpau  libvdpau-va-gl  libverto  libvisio  libvlc  libvorbis  libvpl  libvpx  libwacom  libwebp  libwireplumber  libwnck3  libwpd  libwps  libx11  libxau  libxaw
                  libxcb  libxcomposite  libxcrypt  libxcursor  libxcvt  libxdamage  libxdmcp  libxext  libxfixes  libxfont2  libxft  libxi  libxinerama  libxkbcommon  libxkbcommon-x11  libxkbfile
                  libxklavier  libxml2  libxmlb  libxmu  libxpm  libxpresent  libxrandr  libxrender  libxres  libxshmfence  libxslt  libxss  libxt  libxtst  libxv  libxxf86vm  libyaml  libzmf  lilv
                  linux-headers  lld  llvm  llvm-libs  lm_sensors  lmdb  lpsolve  lsof  luajit  lxqt-config  lz4  lzo  m4  make  mbedtls  md4c  mdadm  menu-cache  mesa  mesa-utils  milou  minizip
                  mission-center  mkinitcpio-busybox  modemmanager  modemmanager-qt  mpdecimal  mpfr  mpv  mtdev  muffin  mujs  muparser  nasm  ncurses  nemo  neon  nettle  networkmanager  networkmanager-qt
                  nftables  ninja  nmap  npth  nspr  nss  ocl-icd  onetbb  openal  opencore-amr  opencv  openexr  openh264  openjpeg2  openjph  openssh  openssl  opus  orc  ostree  oxygen  p11-kit  pacman
                  pahole  pam  pango  pangomm-2.48  patch  pavucontrol  pciutils  pcre  pcre2  perl  phonon-qt6  phonon-qt6-vlc  pinentry  pipewire  pipewire-audio  pipewire-jack  pipewire-pulse  pixman
                  pkgconf  plasma-activities  plasma-activities-stats  plasma-browser-integration  plasma-desktop  plasma-disks  plasma-firewall  plasma-integration  plasma-nm  plasma-pa  plasma-sdk
                  plasma-systemmonitor  plasma-thunderbolt  plasma-vault  plasma-welcome  plasma-workspace  plasma5support  plymouth  plymouth-kcm  polkit  polkit-gnome  polkit-kde-agent  polkit-qt6  poppler
                  poppler-glib  poppler-qt6  popt  portaudio  portmidi  portsmf  postgresql-libs  powerdevil  ppp  print-manager  prison  procps-ng  protobuf  proton-authenticator-bin  pulseaudio-qt  purpose
                  python-cryptography  python-dbus  python-evdev  python-gobject  python-lxml  python-pillow  python-psutil  python-pycups  python-yaml  qca-qt6  qcoro  qpdf  qqc2-breeze-style
                  qqc2-desktop-style  qrcodegencpp-cmake  qt6-5compat  qt6-base  qt6-declarative  qt6-imageformats  qt6-location  qt6-multimedia  qt6-multimedia-ffmpeg  qt6-positioning  qt6-quick3d
                  qt6-quicktimeline  qt6-sensors  qt6-shadertools  qt6-speech  qt6-svg  qt6-tools  qt6-virtualkeyboard  qt6-wayland  qt6-webchannel  qt6-webengine  qt6-websockets  qt6-webview  qtkeychain-qt6
                  raptor  rasqal  rav1e  re2  readline  redland  ripgrep  rnnoise  rtkit  rubberband  rustup  sane  sane-airscan  sbc  sddm  sddm-kcm  sdl2-compat  sdl3  sdl3_ttf  sed  serd  shaderc  shadow
                  shared-mime-info  signal-desktop  signon-kwallet-extension  signon-plugin-oauth2  signon-ui  signond  skanpage  slang  snappy  socat  solid  sonnet  sord  spandsp  spectacle  spirv-tools
                  sqlite  sratom  srt  startup-notification  steam  strace  sudo  suil  svt-av1  syndication  syntax-highlighting  system-config-printer  systemd-libs  systemsettings  taglib  talloc  tar  tdb
                  timezonemap  tinysparql  tslib  twolame  uchardet  udisks2  upower  usbutils  util-linux  util-linux-libs  vamp-plugin-sdk  verdict  vid.stab  vim  vlc-cli  vlc-gui-qt  vlc-plugin-a52dec
                  vlc-plugin-alsa  vlc-plugin-archive  vlc-plugin-dav1d  vlc-plugin-dbus  vlc-plugin-dbus-screensaver  vlc-plugin-faad2  vlc-plugin-ffmpeg  vlc-plugin-flac  vlc-plugin-gnutls
                  vlc-plugin-inflate  vlc-plugin-journal  vlc-plugin-jpeg  vlc-plugin-lua  vlc-plugin-mpg123  vlc-plugin-ogg  vlc-plugin-opus  vlc-plugin-png  vlc-plugin-pulse  vlc-plugin-shout
                  vlc-plugin-speex  vlc-plugin-tag  vlc-plugin-theora  vlc-plugin-twolame  vlc-plugin-vorbis  vlc-plugin-vpx  vlc-plugin-xml  vlc-plugins-base  vlc-plugins-video-output  vmaf  volume_key
                  vscodium-bin  vte-common  vte3  vulkan-icd-loader  vulkan-intel  vulkan-mesa-implicit-layers  vulkan-mesa-layers  vulkan-tools  wacomtablet  wavpack  wayland  wayland-utils  webkit2gtk
                  webkit2gtk-4.1  webrtc-audio-processing-1  weston  wget  which  wine  wireplumber  woff2  wpa_supplicant  wxwidgets-common  wxwidgets-gtk3  x264  x265  xapp  xcb-util  xcb-util-cursor
                  xcb-util-image  xcb-util-keysyms  xcb-util-renderutil  xcb-util-wm  xdg-dbus-proxy  xdg-desktop-portal  xdg-desktop-portal-gtk  xdg-desktop-portal-kde  xdg-desktop-portal-xapp  xdg-user-dirs
                  xdotool  xf86-input-libinput  xf86-input-wacom  xmlsec  xorg-iceauth  xorg-server  xorg-setxkbmap  xorg-xauth  xorg-xdpyinfo  xorg-xinit  xorg-xkbcomp  xorg-xmessage  xorg-xprop  xorg-xrandr
                  xorg-xrdb  xorg-xwayland  xterm  xvidcore  xxhash  xz  yasm  zenity  zeromq  zimg  zint  zix  zlib  zlib-ng  zstd  zxing-cpp
Optional For    : tzdata
Conflicts With  : None
Replaces        : None
Installed Size  : 48,91 MiB
Packager        : Frederik Schwan <freswa@archlinux.org>
Build Date      : Mon Feb 9 12:31:58 2026
Install Date    : Mon Mar 23 20:48:45 2026
Install Reason  : Installed as a dependency for another package
Install Script  : Yes
Validated By    : Signature

backup file: glibc: /etc/locale.gen (Modification time mismatch)
backup file: glibc: /etc/locale.gen (Size mismatch)
backup file: glibc: /etc/locale.gen (SHA256 checksum mismatch)
glibc: 1625 total files, 0 altered files
[motherfucker_big_scorpio@Nexus ~]$

Seems OK if I interpret it correctly?

seth · 2026-04-06 16:22:12

Yup, I was wondering whether there might be some stale glibc AUR package…
Have you run memtest86+ to rule out bad RAM?

Big Scorpio · Yesterday 19:53:18

Positive

Next i shall attempt to surgically "overinstall" Arch Linux like I saw in my other thread ( https://bbs.archlinux.org/viewtopic.php … 8#p2293598 )

seth · Yesterday 19:59:04

Meaningful memtest runs are measured in days, at least run it over night (16h+)

Since there're no huge deviations in the package database it is very unlikely that re-installing anything will do something, but
see this

Apr 03 17:30:25 Nexus kernel: zswap: loaded using pool zstd
Apr 03 17:30:27 Nexus systemd[1]: Starting Create swap on /dev/zram0...

You can have zswap or zram, not both (it certainly doesn't make any sense, whether it could cause this I'm not so sure)
zswap requires a physical swap device as backup, so

Apr 03 17:30:27 Nexus systemd[1]: Activated swap /dev/disk/by-uuid/826ae0ac-254c-4146-adec-1972158dbf9e.

would have to stay.

Arch Linux

#1 2026-04-03 18:25:56

KDE Plasma Wayland can't log in. kickback to login screen

#2 2026-04-04 17:35:26

Re: KDE Plasma Wayland can't log in. kickback to login screen

#3 2026-04-04 20:11:56

Re: KDE Plasma Wayland can't log in. kickback to login screen

#4 2026-04-05 14:35:43

Re: KDE Plasma Wayland can't log in. kickback to login screen

#5 2026-04-05 17:36:04

Re: KDE Plasma Wayland can't log in. kickback to login screen

#6 2026-04-06 15:57:10

Re: KDE Plasma Wayland can't log in. kickback to login screen

#7 2026-04-06 16:22:12

Re: KDE Plasma Wayland can't log in. kickback to login screen

#8 Yesterday 19:53:18

Re: KDE Plasma Wayland can't log in. kickback to login screen

#9 Yesterday 19:59:04

Re: KDE Plasma Wayland can't log in. kickback to login screen

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