How would you deal with people that are assessed a fine as legal punishment, but there are no funds to pay the fine?

If you are assessed a fine, have money, and refuse to pay, you’re thrown in jail.

But what if you’re assessed a fine and simply don’t have the money, or an acceptable way of raising it (say selling a second car).

For instance, sometimes Community Service can be ordered instead.

I understand this is a large (and growing) problem in the US. Some states mandate mandatory minimum fines for some offenses, so the local judge charged with carrying out the law would have no leeway.