Invalid Port Exposed error

[dejwsz]

I had such error " Invalid Port Exposed (Possible Bug)" with that part in my Dockerfile:

ARG PORT=5000
ENV PORT $PORT
EXPOSE $PORT

Is that a wrong approach? The idea behind is to have an option to steer the exposed port value during a build time.

[baruchoxman]

Same here. Looks like a false-positive error..