Problem Creating Image

I am trying to refresh my container base image like this, but couldn’t, so I tried with the default debian.yaml, which I’ve downloaded from Github today:

$ sudo distrobuilder  build-dir ./debian-github.yaml rootfs  --cache-dir /var/tmp/distrobuilder-build-cache/ --timeout 7200  -o image.serial=20260501_14:07 -o image.architecture=amd64  -o source.variant=boot -o image.release=trixie -o image.variant=minbase
INFO   [2026-05-01T14:16:55+01:00] Downloading source                           
I: Target architecture can be executed
E: unsupported variant
Error: Error while downloading source: Failed to run "debootstrap": exit status 1
ERROR  [2026-05-01T14:16:55+01:00] Failed running distrobuilder                  err="Error while downloading source: Failed to run \"debootstrap\": exit status 1"
INFO   [2026-05-01T14:16:55+01:00] Removing cache directory

Regardless of what I try to specify for “image.variant”, it doesn’t work. I’ve tried omitting this option, specifying “default”, or “cloud”, or “minbase”, as shown in the example. This is distrobuilder 3.2 on a Trixie machine, and as part of incus 1:6.23-debian13-202604261518. I’ve tried with 1:6.21… before, but upgraded to test against the latest release.

So far, my understanding was that I could specify arbitrary values for “variant” in the YAML file, which function much like tags in Ansible, then specify one of these on the command line.

If I just run not distrobuilder build-dir, but distrobuilder build-incus instead and omit those flags, then the same YAML file works:

$ sudo distrobuilder build-incus debian-github.yaml --vm -o image.architecture=amd64 -o image.release=trixie

How should I debug this issue, and why does specifying --debug not give any additional output, please?