While I started responding like this:

for variant a. another c'tor (taking 3 args) would be then needed as well (the third arg being assigned to this fLookForStuck thread final...

I somehow based on intuition (?) looked in the current junit head and surprisingly, there the code had been changed since my  branching already really as you suggested: there is in fact a `private final boolean fLookForStuckThread` and well yet another c'tor taking just 2 args `protected Timeout(Timeout t, boolean lookForStuckThread)`...

So what about (1) merging in the changes from head to my branch, and (2) making (cf. head) or keeping (cf. my branch) these fields protected?