There are other models other than two extremes. For example, in (at least some) European countries there is not such thing as private person going bankrupt. However, of course that that person won't be sold to slavery. Simply, if you can not repay the loan, your property will be confiscated and sold to repay it. You can dodge that by not having any property on your name, of course, and most such people do that, but that also means having no flow on your bank account (everything over a small life-sustaining minimum would be taken every month).
That is at least in theory. Since a considerable part of the economy is in the gray zone, there are ways of dodging that. Large part of the law system is corrupt, so well connected people always find a way to be untouchable. The system is also inefficient so lots of those debts exist just on paper.
Basically, you can't go bankrupt as a person, and you wont be sold to slavery, but you will effectively still own the debt and the only way to not repay it is to work in the black zone outside of the system, or wait so long that the lenders write it off themselves (after a few decades or so?).
Ok. In this model, you keep one of your basic rights (freedom) but forever loses another (right to have any property). I'd call this a "semi-slavery" model.
At least in some "debtor's jail" systems you could get your rights back after spending some time incarcerated.
That is at least in theory. Since a considerable part of the economy is in the gray zone, there are ways of dodging that. Large part of the law system is corrupt, so well connected people always find a way to be untouchable. The system is also inefficient so lots of those debts exist just on paper. Basically, you can't go bankrupt as a person, and you wont be sold to slavery, but you will effectively still own the debt and the only way to not repay it is to work in the black zone outside of the system, or wait so long that the lenders write it off themselves (after a few decades or so?).