Recipe for building Java program fails due to memory limits

I'm running builds for my program 'patchworker' using the bazaar recipe system, but some of the builds are failing when the dependencies are installed.

During the setup of ca-certificates-java the package installation fails, likely due to a memoy restriction; java can't allocate enough heap space:
Error occurred during initialization of VM
Could not reserve enough space for object heap
Could not create the Java virtual machine.
(From https://launchpadlibrarian.net/88141845/buildlog.txt.gz )

This sometimes doesn't happen, perhaps because some build targets have larger memory caps?

This is the recipe I'm using:
https://code.launchpad.net/~w-shackleton/+recipe/patchworker

Any ideas on what to do?
Thanks