The poweroff menu is not working in ubiquity-only install mode

[Po-Hsu Lin]

Steps:
 1. Create a Live USB with Disco daily image (20190331)
 2. Boot with the Live USB, it should take you to the installation screen directly
 3. Click on the upper right icon sets to expand the menu
 4. Click on the power icon

Expected result:
 * A menu should pop-up and asking user what to do (reboot / poweroff)

Actual result:
 * Nothing happens (it works in the Live session after clicking on the Try Ubuntu button)

gnome-shell 3.32.0-1ubuntu1

[Po-Hsu Lin (cypressyew)]

Tested on a Dell Inspiron 7737.

[Daniel van Vugt (vanvugt)]

Does this laptop have any external monitor plugged in?

[Po-Hsu Lin (cypressyew)]

Nope, just with the laptop screen.

[Po-Hsu Lin (cypressyew)]

I have this checked on another laptop (Dell G7 7588) with the same 20190331 image, and it's still affected.

[Po-Hsu Lin (cypressyew)]

This issue still exist with the latest image (20190403)

[Sebastien Bacher (seb128)]

Thank you for your bug report. Did it work in previous cycle? It could be a bug in the ubiquity shell mode, that fuinction is not a major one anyway since you usually don't want to stop the computer in the middle of an installation

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Po-Hsu Lin (cypressyew)]

Yeah,
I can see this with Bionic as well.

[Daniel van Vugt (vanvugt)]

Thank you for taking the time to report this bug and helping to make Ubuntu better. This particular bug has already been reported and is a duplicate of bug 1715602, so it is being marked as such. Please look at the other bug report to see if there is any missing information that you can provide, or to see if there is a workaround for the bug. Additionally, any further discussion regarding the bug should occur in the other report. Feel free to continue to report any other bugs you may find.