Exclude a job from a particular runner

How could I make sure a particular specific runner doesn’t pick up a given job?

The issue is have a runner that doesn’t have enough resources (RAM) to run a job. It can run most of the jobs in a pipeline but not one or two. Otherwise, all the jobs would be happily run on specific or shared runners, the jobs have only the docker tag (which my specific runner also has).

The only solution I can find is abusing one of the tags that happen to be present in shared runners (e.g. mongo), even though I don’t need it, use it, or even know what it is; and add that tag to the “big” job and to any other specific runners I may have that are capable of running the job. This has the inconvenience of being fragile (the tag could disappear from shared runners) and obscure (for maintenance).

What I would really need is some way of specifying minimum requirements (beyond just tags) for jobs, along with available resources for runners… But I don’t think that’s possible right now. Is there any relevant issue to track?