[Checkbox-Hilden] Error message pop-up when resume checkbox-hilden

[Ray Chen]

[Summary]
When resume checkbox-hilden got message
Failed to disable unit: Unit file plainbox-autostart.service does not exist.
rm: cannot remove '/etc/systemd/system/plainbox-autostart.service': No such file or directory

[Steps to reproduce]
1. Install checkbox-hilden-classic
2. launch checkbox-hilden-classic.test-runner
3. Ctrl-C to exit Checkbox session and resume checkbox again

[Expected result]
No error message after resume checkbox

[Actual result]
Got error message and output as below, checkbox work normal without issues only this error message

ubuntu@ubuntu:~$ checkbox-hilden-classic.test-runner
=========================[ Resume Incomplete Session ]==========================
There is 1 incomplete session that might be resumed
Do you want to resume session 'test-runner-2020-06-16T08.12.22'?
  r => resume this session
  n => next session
  c => create new session
  d => delete old sessions
[rncd]: r
Failed to disable unit: Unit file plainbox-autostart.service does not exist.
rm: cannot remove '/etc/systemd/system/plainbox-autostart.service': No such file or directory
Previous session run tried to execute job: com.canonical.certification::fwts
What do you want to do with that job?
  s => skip that job
  p => mark it as passed and continue
  f => mark it as failed and continue
  r => run it again

[Failure rate]
100%
[Additional information]
SKU:202004-27815
Image:
cat /etc/buildstamp
Ubuntu 18.04.4 LTS - amd64 (20200612-02:44)
serial=20200610.1
orig_prefix=bionic-server-cloudimg
suite=bionic
build_name=server
project=hilden

system-manufacturer: Default string
system-product-name: Default string
bios-version: 5.0.1.3
CPU: Intel(R) Core(TM) i3-8100T CPU @ 3.10GHz (4x)
GPU: 00:02.0 VGA compatible controller [0300]: Intel Corporation Device [8086:3e91]
kernel-version: 4.15.0-106-lowlatency

[Ray Chen (ray.chen)]

Automatically attached

[Ray Chen (ray.chen)]

Automatically attached

[Ray Chen (ray.chen)]

Automatically attached

[Ray Chen (ray.chen)]

Automatically attached

[Ray Chen (ray.chen)]

when I run $checkbox-hilden-classic.checkbox-cli run com.canonical.certification::power-management-reboot-poweroff-cert-automated
I found the system running power-off and power-on automatically, but checkbox doesn't resume after system login to desktop (autologin is enabled)

[Ray Chen (ray.chen)]

Here is the checkbox remote error message

-----------------------------[ Running job 3 / 6 ]------------------------------
-------------------------[ power-management/poweroff ]--------------------------
ID: com.canonical.certification::power-management/poweroff
Category: Power Management tests
--------------------------------------------------------------------------------
Unable to determine invoking user

the user name/password is ubuntu/ubuntu