lxd-imagebuilder fits within the supported category of compilers - however, given the original list of requirements for distrobuilder in Request for classic confinement: distrobuilder I wonder if it might be possible to try and strictly confine lxd-imagebuilder in the future? @tomp could you please try and look into this in the future?
For now, the requirements for classic confinement are understood and I have vetted the publisher. This is now live.