anchor.diff:  
       # Test gpg-agent starting pinentry-gnome3 via D-Bus (tests if
       # $WAYLAND_DISPLAY is correctly imported into the D-Bus user env):
  -    machine.succeed(
  -        "su - alice -c 'swaymsg -- exec gpg --no-tty --yes --quick-generate-key test'"
  -    )
  +    swaymsg("exec gpg --no-tty --yes --quick-generate-key test")
       machine.wait_until_succeeds("pgrep --exact gpg")
       machine.wait_for_text("Passphrase")
       machine.screenshot("gpg_pinentry")
  
positive.code:     machine.screenshot("sway_exit")
  
      # Exit Sway and verify process exit status 0:
      machine.succeed("su - alice -c 'swaymsg exit || true'")
      machine.wait_until_fails("pgrep -x sway")
      machine.wait_for_file("/tmp/sway-exit-ok")
    '';
  
negative.code:   enableOCR = true;
  
    testScript = { nodes, ... }: ''
      import shlex
  
      def swaymsg(command: str, succeed=True):
          with machine.nested(f"sending swaymsg {command!r}" + " (allowed to fail)" * (not succeed)):
            (machine.succeed if succeed else machine.execute)(
              f"su - alice -c {shlex.quote('swaymsg -- ' + command)}"
            )
  
      start_all()
      machine.wait_for_unit("multi-user.target")
  
  