[Docker] how to solve 'VOLUME: not found' or 'COPY: not found'

If you receive a "/bin/sh: COPY: command not found" (or VOLUME) error, you should check that previous Dockerfile line is closed properly. For example, if you have similar like below,

RUN set -eux; \
   apk add --no-cache --virtual .build-deps \
      git \
   ;

do not forget to enclose your line with \ and ; symbols.