How do I debug a Linux crash?

I recently released my game on Steam and I’m receiving some reports about crashes on Ubuntu. The game pops up the config dialog, but crashes immediately upon pressing Play. No crash in Windows or Mac. I’m not very familiar with Linux and would like to know the steps I need to take to learn more about why it is crashing and how to fix. (How to find / read crash dumps, etc.)

Thanks!

Get a Linux machine and have it on the same network as your development machine. Then you can run a dev build on linux and it should show up as target in the Mono Develop debugger.
That should get you started.