ln: failed to create symbolic link '/etc/localtime': File exists

Problem running this command...

$ docker build -t archlinux .
...
Generating locales...
  en_US.UTF-8... done
Generation complete.
ln: failed to create symbolic link '/etc/localtime': File exists
The command '/bin/sh -c setup-arch-docker-container' returned a non-zero code: 1

Can you help me?
Thanks