• This is a bug report
• This is a feature request
• I searched existing issues before opening this one

Expected behaviour

Success

Actual behaviour

DL3061 error: Invalid instruction order. Dockerfile must begin with FROM, ARG or comment.

Steps to reproduce the behaviour

A Dockerfile that begin with a comment that starts with 'syntax'

Run:
docker run --rm -i hadolint/hadolint:latest hadolint "$@" - < Dockerfile

Version:
Haskell Dockerfile Linter v2.9.1-0-g42d0378-dirty

Error:

-:1 DL3061 error: Invalid instruction order. Dockerfile must begin with `FROM`, `ARG` or comment.

Dockerfile

# syntax=something
ARG FOO=BAR
FROM debian:8

Additional environment details (OS, stack version, etc.)
Using hadolint/hadolint:2.8.0-debian works