Bug#733546: gdm3: stuck on GNU/kFreeBSD while "trying to open reauthentication channel"

[Robert Millan]

Package: gdm3
Version: 3.8.4-6
Severity: important
User: debian-bsd at lists.debian.org
Usertags: kfreebsd

On GNU/kFreeBSD, gdm3 gets stuck after typing login credentials. Note
that this doesn't happen when auto-login has been enabled (in which
case gdm3 works fine).

$ sudo gdm3
[...]
gdm3[62765]: GdmSlaveProxy: Running command: /usr/lib/gdm3/gdm-simple-slave --display-id /org/gnome/DisplayManager/Displays/_0
gdm3[62765]: GdmSlaveProxy: Started slave with pid 62766
gdm3[62765]: GdmDisplay: Setting slave bus name::1.152 on display :0
gdm3[62765]: GdmSlave: Got timed login details for display :0: 0 '(null)' 0
gdm3[62765]: GdmSlave: Got timed login details for display :0: 0 '(null)' 0
gdm3[62765]: GdmSlave: Got timed login details for display :0: 0 '(null)' 0
gdm3[62765]: GdmManager: trying to open reauthentication channel for user rmh
[ stuck with no progress ]

-- System Information:
Debian Release: jessie/sid
  APT prefers unstable
  APT policy: (500, 'unstable'), (1, 'experimental')
Architecture: kfreebsd-amd64 (x86_64)

Kernel: kFreeBSD 10.0-0-amd64
Locale: LANG=ca_AD.UTF-8, LC_CTYPE=ca_AD.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash