Why won't the container start?

Question

Docker

Here is such a Dockerfile:

FROM debian:stable-slim
ENV PATH /bin:/usr/bin:/usr/loca/sbin:/usr/sbin:/sbin
RUN apt-get update
RUN apt-get -y install nginx python3 python3-pip
ADD . /source
EXPOSE 80
EXPOSE 443

On startup it gives an error:

docker: Error response from daemon: OCI runtime create failed: container_linux.go:348: starting container process caused "exec: \"-n\":
 executable file not found in $PATH": unknown.

How can this be fixed?