The mode check returned 1 without any output, so a launch from the app
menu died after the polkit prompt with nothing to diagnose. Name each
source directory and the mode it was left with.
A numeric chmod keeps setuid/setgid on a directory, so a setgid ~/Windows
stayed 2700 and failed the exact 700 privacy check, aborting the launch.
dockur marks an initially empty /shared setgid (chmod 2777) on first boot,
so this hits fresh installs the next time the bind anchors are recreated.