Passing --scheduler-file will not raise error on wrong arguments

[pentschev]

I just found out that for some reason passing wrong argument names to dask-cuda-worker will not fail when used with --scheduler-file, the following will start:

$ dask-cuda-worker --enable-tcp-over-ucx --enable-nvlink --enable-infiniband --ucx-net-devices=auto --scheduler-file scheduler.json

However, if you pass in the scheduler address it will fail, as the correct argument name is --net-devices:

$ dask-cuda-worker ucx://${SCHEDULER_IP}:8786 --enable-tcp-over-ucx --enable-nvlink --enable-infiniband --ucx-net-devices=auto
Usage: dask-cuda-worker [OPTIONS] [SCHEDULER] [PRELOAD_ARGV]...

Error: no such option: --ucx-net-devices=auto

[pentschev]

After a bit of debugging it seems that the first incorrect option will be understood as being the scheduler argument even if it begins with --, thus if there's only one option that's incorrect it won't fail. This seems to be an intended consequence of click as it aims to be robust to options formatting and not just those starting with --.