Today if we encounter a failure with `ostreecontainer` we just output e.g.
The following error occurred while installing the payload. This is a fatal error and installation will be aborted.The command 'ostree container image deploy --sysroot=/mnt/sysimage --image=192.168.4.22/quay/test/lamp-bootc:latest' exited with the code 1.
which misses the stderr, which is critical for debugging problems.