Interesting idea! Although, maybe you just want to be able to run the configuration language in a reversible debugger? This issue becomes even harder when you

Interesting idea! Although, maybe you just want to be able to run the configuration language in a reversible debugger? This issue becomes even harder when you have some kind of solver involved, like a constraint solver or unification. As a user the solver is supposed to make your life easier but if it rejects something without a good enough error message you are stuck; having to examine the solver code to work out why is a much worse experience than not having a solver. (This is the same issue with clever type systems that need a solver)