flyctl deploy ignores -c parameter for specifying the .toml file

I think this got to be a bug.

I have a project which has two docker containers, and I want to deploy them both to fly.
So i need to toml files, one for each service.

I looked at
fly deploy -h
and found the -c param, this allows me to pass the path to the toml file. It sasy path to configuration file. What else coudl that mean?

So I have the deploy string:
flyctl deploy --local-only -i selenium/standalone-chrome:latest -r fra -c ./fly/fly-selenium-chrome.toml

The service doesnt’ deploy properly, and no change to the toml file helps
LOG_LEVEL=debug fly logs -a selenium-chrome
I can see the message (silently failing without the LOG_LEVEL=debug flag

DEBUG no app config found at /{currentWorkingDirectory}/fly.toml; skipped.

Of course, there is no config there: I explicitly said it was somewhere else. However, when i change the path after -c to a file that does not exist, that tell me no toml file was found there.
So what is going on here? The message is clearly either dead wrong, or using the -c flag is broken at some point.