This is our external CNF Delta-Debugger we have been using since 2007.

External means that we simply delta-debug CNF files. This is enough for stand-alone solvers (such as Kissat, but in general we consider delta-debugging API calls in the context of model-based testing as way superior (as mobical does for CaDiCaL).

In any case you may want to consider option delta-debugging and also externalize as many parameters as possible of your software and turn them into options, such that they can be delta-debugged (and fuzzed in the first place).

And while talking about fuzzing you might want to checkout our CNF fuzzer cnfuzz too (which uses cnfdd in the scripts that come with it).

Automated Testing and Debugging of SAT and QBF Solvers
Robert Brummayer, Florian Lonsing, Armin Biere
Proc. 13th Intl. Conf. on Theory and Applications of Satisfiability Testing (SAT'10)
Lecture Notes in Computer Science (LNCS)
vol. 6175, pages 44-57, Springer 2010
[ paper | bibtex | cnfuzz | cnfdd | qbfuzz | qbfdd ]