upgrading postmarketos-ui-phosh causes phosh to restart

Describe your issue

What's the expected behaviour?

reinstalling/upgrading postmarketos-ui-phosh should not cause phosh to automatically restart

What's the current behaviour?

phosh is restarted. this is a problem because if the upgrade is happening in a terminal (or gnome-software?) in the UI, then apk will be killed before the upgrade finishes and it's impossible to complete it without SSHing. Future attempts to re-run the upgrade within the UI will be killed prematurely by phosh restarting.

I'm not sure if other ui packages have this problem too...

How to reproduce your issue?

With phosh, in kgx:

$ apk fix -r postmarketos-ui-phosh
<phosh is restarted>

What device are you using?

device-purismlibrem5`

On what postmarketOS version did you encounter the issue?

• edge (master branch)
• v21.06
• v21.12

On what environment did you encounter the issue?

Phone environments

• Phosh
• Plasma Mobile
• Sxmo (Wayland/Sway)

How did you get postmarketOS image?

• from https://images.postmarketos.org
• I built it using pmbootstrap
• It was preinstalled on my device

What's the build date of the image? (in yyyy-mm-dd format)

1 year ago

Additional information

I haven't looked into this much yet, but here's the output from running apk fix (there's nothing that stands out here...):

librem5:~$ sudo apk fix -r postmarketos-ui-phosh
fetch http://dl-cdn.alpinelinux.org/alpine/edge/main/aarch64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/edge/community/aarch64/APKINDEX.tar.gz
fetch http://dl-cdn.alpinelinux.org/alpine/edge/testing/aarch64/APKINDEX.tar.gz
fetch http://mirror.postmarketos.org/postmarketos/master/aarch64/APKINDEX.tar.gz
(1/1) Reinstalling postmarketos-ui-phosh (13-r1)
Executing postmarketos-ui-phosh-13-r1.post-upgrade
 * rc-update: tinydm already installed in runlevel `default'; skipping
 * rc-update: modemmanager already installed in runlevel `default'; skipping
 * rc-update: bluetooth already installed in runlevel `default'; skipping
 * rc-update: iio-sensor-proxy already installed in runlevel `default'; skipping
 * rc-update: networkmanager already installed in runlevel `default'; skipping
tinydm: Session already set to: /usr/share/wayland-sessions/phosh.desktop
tinydm: To change it, run: 'tinydm-set-session -f -s /usr/share/wayland-sessions/phosh.desktop'
Executing busybox-1.34.1-r4.trigger
Executing glib-2.70.1-r0.trigger
Executing postmarketos-base-16-r0.trigger

I also don't see any explicit rc-service tinydm restart anywhere in pmaports