qvm-run --gui waits indefinetly for GUI application even if gui feature is disabled

[ben-grande]

Qubes OS release

Qubes OS 4.2

Brief summary

I have qubes with the gui feature disabled, but qvm-run --gui (default is to use GUI), waits indefinitely when I try to open a GUI application. It does not print stdout or stderr, but waits for the session first, therefore not even returning if the command failed.

Steps to reproduce

1. qvm-features disp-sys-usb gui ''
2. qvm-start disp-sys-usb
3. Try to run commands that require a GUI

$ qvm-run -p -- disp-sys-usb xterm
^C%

$ qvm-run -p --no-gui -- disp-sys-usb xterm
xterm: Xt error: Can't open display: :0

Expected behavior

1. Don't wait for GUI when gui feature is disabled.
2. Exit when subprocess terminates

Actual behavior

Waits for GUI even though it doesn't have one.

Additional information

I don't how it should consider also gui-emulated or emulated VGA.