> I think that no potential or current employer has ever given a rat's ass about open source contributions, and do not consider that work as valuable when making hiring decisions.

That is not the case with the D programming language effort. Quite a number of strong D open-source contributors have been recruited into very well paying positions directly because of their contributions.

I suspect the key is contributing to a higher profile open source project. One that is high enough that one can make major contributions, and not so high that one has a hard time standing out amongst the other contributors.