I am trying to create a docker image in a ubuntu terminal and the above error occurs. How can I fix this?

lbuntulip-172-31-21-129: $ sudo systemctl start jenkins ubuntulip-172-31-21-129: \$ sudo systemctl enable jenkins Synchronizing state of jenkins.service with Sysv service script with /lib/systemd/systemd-sysv-install. axecuting: /lib/systemd/systemd-sysv-install enable jenkins dbuntulip-172-31-21-129: \$ docker build -f Dockerfile -t myapp. +] Building 0.3s (2/2) FINISHED [internal] load . dockerignore > transferring context: 2B [internal] load build definition from Dockerfile > transferring dockerfile: 2B