Klever

To enforce computational resource limits we use BenchExec which supported units even in version 1.7 we used before recent changes. Our format allows to specify limits for verification tasks just in bytes and milliseconds which isn't convenient. Limits for verification jobs can be specified in a Bridge form where unit GB is for memory and min is for time (both numbers are floats) - I think that can be remained as is.

To keep backward compatibility I suppose to still interpret limits without units as bytes and milliseconds for memory and time correspondingly.