Contrary to expectation, lowering the maxSuccess parameter may cause tests to fail:

> let p k k' = k /= k' ==> (k :: Int) /= k'
> quickCheckWithResult stdArgs p
+++ OK, passed 100 tests; 11 discarded.
> quickCheckWithResult stdArgs{maxSuccess=2} p
+++ OK, passed 2 tests; 11 discarded.
> quickCheckWithResult stdArgs{maxSuccess=1} p
*** Gave up! Passed only 0 tests; 10 discarded tests.

The explanation seems to be due to a combination of:

• discard ratio defaults to 10, which means we allow only 10 discarded results in total for the case maxSuccess=1 (maxSuccess=2 gets 20 discards upfront)
• computeSize doesn't ramp up the size quickly enough, it starts out [0,0,0,0,0,0,0,0,0,1,1,1,1,1,1,1,1,1,1,2,2,2... regardless of maxSuccess parameter

Those computed sizes in particular seem a bit weird to me, but I can't say I have any kind of understanding of most of what's going on here. It does seem a bit at odds with the comment here