pi-gen build fails while creating loop devices.
This issue is related to https://github.com/mariolukas/FabScanPi-Server/issues/130 and https://github.com/mariolukas/FabScanPi-Build-Raspbian/issues/10
The script should build by using the latest release tag ( buster ). I was able to build it when buster was release around the time when the pi 4 was announced.
git fetch && git fetch --tags git checkout 2019-06-20-raspbian-buster
I think it is a better approach to use a stable tagged version of pi-gen. This is why I added a tag checkout for the current build script 3 days ago. ( https://github.com/mariolukas/FabScanPi-Build-Raspbian/blob/master/build-fabscan.sh#L4 )
I left them an open issue over at pi-gen. The folders aren't even being made so there must be some error on their side with the build scripts. No work folder, no deploy folder but losetup reports that the DD-MM-YY-raspian.img is mounted so I'm at a loss. I don't know enough about the process to really help them either.