`jobs:` is ignored

I have a ruby yaml with macos + linux x rvm.
I would like to add few windows runs to the matrix, but I can’t achieve that.

When I add os to the list of oses, I’m getting error that ruby is not supported.
When I try to add using jobs, like:

jobs:
  include:
    - os: windows

Nothing happens.

How can i achieve this?

Try:

jobs:
  include:
    - os: windows
      cache: false

See if that works.

Ok, I found the reason jobs didn’t work. Because I have matrix and jobs and there is a config warning (which should be an error I presume):

root: both matrix and jobs given, matrix overwrites jobs
root: key matrix is an alias for jobs, using jobs

And this warning is really hardly discoverable when build starting. You should go to the view config (which has green indicator) and see that something is wrong.