Bug#973933: sddm: Unable to open env file: /etc/environment: No such file or directory

[Diederik de Haas <didi.debian@cknow.org>]

Package: sddm
Version: 0.19.0-1
Followup-For: Bug #973933

Got a very big upgrade (hadn't started my Sid system for several days), which 
included sddm and after a reboot I got the sddm login screen.
But after giving my credentials, I got thrown back to the login screen.
'systemctl status sddm.service' told me:
Unable to open env file: /etc/environment: No such file or directory


● sddm.service - Simple Desktop Display Manager
     Loaded: loaded (/lib/systemd/system/sddm.service; enabled; vendor preset: enabled)
     Active: active (running) since Mon 2020-11-09 23:14:48 CET; 8min ago
       Docs: man:sddm(1)
             man:sddm.conf(5)
   Main PID: 3641 (sddm)
      Tasks: 27 (limit: 77031)
     Memory: 35.6M
     CGroup: /system.slice/sddm.service
             ├─3641 /usr/bin/sddm
             └─3854 /usr/lib/xorg/Xorg -nolisten tcp -auth /var/run/sddm/{a330fe19-b614-4bb4-9329-d7d6240b8ca7} -background none -noreset -displayfd 18 -seat seat0 vt7

nov 09 23:15:58 bagend sddm[3641]: Socket server started.
nov 09 23:15:58 bagend sddm[3641]: Loading theme configuration from "/usr/share/sddm/themes/debian-maui/theme.conf"
nov 09 23:15:58 bagend sddm[3641]: Greeter starting...
nov 09 23:15:58 bagend sddm-helper[3885]: [PAM] Starting...
nov 09 23:15:58 bagend sddm-helper[3885]: [PAM] Authenticating...
nov 09 23:15:58 bagend sddm-helper[3885]: [PAM] returning.
nov 09 23:15:58 bagend sddm-helper[3885]: pam_unix(sddm-greeter:session): session opened for user sddm by (uid=0)
nov 09 23:15:58 bagend sddm-helper[3885]: pam_env(sddm-greeter:session): Unable to open env file: /etc/environment: No such file or directory
nov 09 23:15:58 bagend sddm[3641]: Greeter session started successfully
nov 09 23:15:58 bagend sddm[3641]: Message received from greeter: Connect

I indeed do not have that file (I do have /etc/environment.d/90qt-a11y.conf), 
but that shouldn't make sddm crash.
Downgrading sddm and sddm-theme-debian-maui to the testing version
(0.18.1-1) made me able to login again.
After sending this bug report, I'll try to see whether a 'touch
/etc/environment' would fix the problem as well.
Anyway, it shouldn't have crashed on it imo.

Notable difference with OP is that I use KDE as my DE.

Cheers,
  Diederik

-- System Information:
Debian Release: bullseye/sid
  APT prefers unstable-debug
  APT policy: (500, 'unstable-debug'), (500, 'unstable'), (500, 'testing'), (101, 'experimental')
Architecture: amd64 (x86_64)

Kernel: Linux 5.9.0-1-amd64 (SMP w/16 CPU threads)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)
LSM: AppArmor: enabled

Versions of packages sddm depends on:
ii  adduser                 3.118
ii  debconf [debconf-2.0]   1.5.74
ii  libc6                   2.31-4
ii  libgcc-s1               10.2.0-16
ii  libpam0g                1.3.1-5
ii  libqt5core5a            5.15.1+dfsg-2
ii  libqt5dbus5             5.15.1+dfsg-2
ii  libqt5gui5              5.15.1+dfsg-2
ii  libqt5network5          5.15.1+dfsg-2
ii  libqt5qml5              5.15.1+dfsg-3
ii  libqt5quick5            5.15.1+dfsg-3
ii  libstdc++6              10.2.0-16
ii  libsystemd0             246.6-2
ii  libxcb-xkb1             1.14-2
ii  libxcb1                 1.14-2
ii  qml-module-qtquick2     5.15.1+dfsg-3
ii  x11-common              1:7.7+21
ii  xauth                   1:1.0.10-1
ii  xserver-xorg [xserver]  1:7.7+21

Versions of packages sddm recommends:
pn  haveged                              <none>
ii  libpam-systemd                       246.6-2
ii  sddm-theme-debian-maui [sddm-theme]  0.19.0-1

Versions of packages sddm suggests:
ii  libpam-kwallet5           5.19.5-3
pn  qtvirtualkeyboard-plugin  <none>

-- debconf information:
  sddm/daemon_name: /usr/bin/sddm
* shared/default-x-display-manager: sddm