CPUS_PER_TASK per-se is not buggy : it allows users to specify how many cores they need per task (for example, if the task requires 4 cores per task in case it is doing something non trivial).
The default is 1 - folks who customize this value would probably know what they are doing (and ensure cores per worker is a multiple of CPUS_PER_TASK, for example).

I assumed you meant about availableCpus variable.