I have version v0.7.2.0-g32a928e-beta and -gen option seems to be there.

I will try it, just to see if I'm lucky, but many thanks for the comments about the very very low probability.

Which tool would you recommend for solo mining in Linux (nVidia card)?

I just want to give it some use, as the computer is always switched on for other tasks.

I want to test solo to get the feel of it before considering joining a pool. I want to learn about bitcoin, not just to make BTCs with it.

Many thanks