FAQ

Delta debugging is slow

Read the section about how to speed up delta debugging.

ddSMT seems to be stuck in an infinite loop

All modifications performed by ddSMT should simplify the input, or more formally, all mutations should make the input smaller with respect to an appropriate ranking function. Also note that some mutators may indeed apply a lot. If you really think ddSMT checks the same input over and over again, try --check-loops.