Comment 1 for bug 2069834

I think option (2) is the probably the "best" fix. Another alternative I can think of is shipping a tmp.mount drop-in on the autopkgtest environment to change the size to something better. E.g.,

# /etc/systemd/system/tmp.mount.d/size.conf
[Mount]
Options=size=<param>

where <param> could be a percentage of RAM (e.g. 75%%), or an explicit size (e.g. 4GB). But then again, these defaults are intentionally easy to override. If the autopkgtest environment wants to do something different, I don't think it's the end of the world, and masking tmp.mount as a first step is fine.

> This under the assumption that the switch to a tmpfs has been discussed, and we want it in Ubuntu.

This was discussed in the foundations team, and the initial consensus was to not deviate from upstream and Debian.