buildx failed with: ERROR: failed to solve: process "/bin/sh -c wget \"${RPI_IMAGE_URL}\" -O \"${RPI_IMAGE_FILE}.xz\" && echo \"${RPI_IMAGE_SHA256} ${RPI_IMAGE_FILE}.xz\" | sha256sum -c - && xz -d ${RPI_IMAGE_FILE}.xz" did not complete successfully: exit code: 1