$ cat Dockerfile 
FROM debian:bullseye-20220912@sha256:3e82b1af33607aebaeb3641b75d6e80fd28d36e17993ef13708e9493e30e8ff9
RUN touch --date=@0 /bin /etc

$ sudo buildctl build --frontend dockerfile.v0 --output type=tar,dest=a.tar --local dockerfile=. --local context=.

$ tar tvf a.tar
drwxr-xr-x 0/0               0 1970-01-01 09:00 bin/
...
drwxr-xr-x 0/0               0 2022-10-04 21:48 etc/
...