/usr/share/xsessions/spectrwm.desktop is in spectrwm 2.6.0-1ubuntu2.
This file is owned by root:root, with mode 0o644.
The actual contents of the file can be viewed below.
1 2 3 4 5 6 | [Desktop Entry]
Name=spectrwm
Comment=The spectrwm window manager
Type=Application
Exec=spectrwm
TryExec=spectrwm
|