Have /tmp cleaned by mounting it as tmpfs

Describe your issue

What's the expected behaviour?

I would expect /tmp to be clean after a reboot.

What's the current behaviour?

Files and directories in /tmp are persistent across reboots.

How to reproduce your issue?

Look into /tmp, you should see some old files. Otherwise write a file to /tmp, reboot and see whether it is still there.

What device are you using?

Pinephone PMOS CE

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)

Other

• No environment
• GNOME
• KDE Plasma
• Kodi
• MATE
• Shelli
• Sway
• Weston
• Xfce4
• fbkeyboard
• i3wm
• Sxmo (Xorg/Dwm)

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)

Unsure, I installed it a couple months ago.

Additional information

Looking at the mount output of my Arch desktop I see:tmpfs on /tmp type tmpfs (rw,nosuid,nodev,nr_inodes=409600,inode64), so presumably something like this would be the solution.

I noticed the issue because Megapixels writes large files to /tmp and fails to clean them up. As a consequence the file system filled up completely and the device became unusable. Luckily I could figure out the cause and recover using SSH.