Running repro in parallel

[kpcyrd]

I'm trying to run repro multiple times (giving each their own $BUILDDIRECTORY) for mass rebuilds but I ran into issues with:

Failed to allocate scope: Unit root.scope already exists

It seems this is because repro builds in /var/lib/repro/root, with root then becoming the machine name in nspawn, which has to be unique.

[Foxboron]

Two problems here

• root scope is because we havent added the --empheral option
• How do we set a unique build directory? Both devtools and repro currently use the username for the overlays.

[FFY00]

This would also be a good improvement to devtools, repro should follow devtools.

The solution here would be to generate an unique directory, eg. user-sdf78fse. This directory would be removed after the build, we could also ship a timer to cleanup unlocked directories in case the process exited before the directory was removed.

[Foxboron]

I have also been contemplating just using $$ and use the PID of the process.

[Foxboron]

Frankly, wouldn't $USER-$$ solve this? Is there any need for a more unique name for these directories?

[FFY00]

Just $$ works but I prefer $USER-$$. I don't see any drawbacks from this approach.

[Foxboron]

Implemented with 6299e1e