Note: The build does not hang when using sbuild with a chroot of type "file", like this:
[bookworm-file] type=file profile=sbuild description=Debian bookworm file=/chroot/bookworm.tar.gz groups=sbuild root-groups=sbuild preserve-environment=true Previously, I was using a chroot of type "directory". This is probably a bug anyway, as there is not a debian/control field to specify the kind of chroot that should be used, but I'll need to investigate a little bit more before making an upload for stable. Thanks.

