What it means
There is a file named Dockerfile at the root of your project, and it has nothing in it. A Dockerfile is the recipe for building a container. With no steps, there is nothing to build.
How to fix it
Delete it. If you do not need a Dockerfile, remove the empty file. Antideploy then builds your project the way it builds any project without one.
Or write it. If you want your own Dockerfile, add the steps it needs. Your start command, and the port you declare with EXPOSE, come from this file.
A small working example for a Node app:
FROM node:22-slim
WORKDIR /app
COPY package*.json ./
RUN npm ci --omit=dev
COPY . .
EXPOSE 3000
CMD ["node", "server.js"]Why it happens
An agent or a template can create the file and never fill it in. Antideploy now declines to build with an empty Dockerfile in the first place, but a failure of this kind can still reach you from an older setup.