Hello, Dear List! I have tests: I'm using HSpec (and QuickCheck too). And I have tests like this: describe "Something" $ do it "something is correct" $ do ...blah-blah... it "any string is correct" $ property $ \s -> all (=='*') (Something s) -- it's for example only!!! so something like unit-test and property checks in one SomethingSpec.hs. I'm running them with this Makefile: .PHONY: test fast-test fast-test: stack exec runhaskell -- -isrc -itest test/Spec.hs test: stack test and in Spec.hs I have: {-# OPTIONS_GHC -F -pgmF hspec-discover #-} That's all. So, when I find failed test, I get a trace like this: ... Failures: test/SomethingSpec.hs:172: 1) BlahBlah.superFunc any string is correct: result Gave up after 48 tests ...etc... So, my question is: when QuichCheck runs my property test, it passes argument to property's lambda. And on 48th test attempt with some concreate argument value my check fails. How can I get detailed output from such test environment, to see what concreate arguments lead to failure? To see something (or similar/or more detailed even): Failed with arguments: s = "" Is it possible (I run them with stack and with runhaskell too) ? === Best regards, Paul