IOSimPOR assertion failures

[coot]

Recently two execution of the propExploration errored:

• https://github.com/input-output-hk/io-sim/actions/runs/4491097750/jobs/7899072815
• https://github.com/input-output-hk/io-sim/actions/runs/4413935534/jobs/7735014212?pr=73

Logs

    propExploration:                           FAIL (36.64s)
      *** Failed! (after 53 tests and 48 shrinks):
      Exception:
        Assertion failed
        CallStack (from HasCallStack):
          assert, called at src/Control/Monad/IOSimPOR/Internal.hs:990:5 in io-sim-0.4.0.0-inplace:Control.Monad.IOSimPOR.Internal
      Tasks [Task [WhenSet 9 0],Task [WhenSet 0 0],Task [WhenSet 10 10,WhenSet 10 9],Task [WhenSet 0 0]]
      Schedule control: ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]
      RacyThreadId [3] delayed at time Time 0s
        until after:
          RacyThreadId [4]
      
      Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventSimStart (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventTxCommitted [] [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventTxCommitted [] [Labelled (TVarId 1) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventThreadForked (RacyThreadId [1]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventThreadForked (RacyThreadId [2]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventThreadForked (RacyThreadId [3]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventThreadForked (RacyThreadId [4]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventTxCommitted [Labelled (TVarId 1) Nothing] [] (Just (Effect {effectReads = fromList [], effectWrites = fromList [TVarId 1], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventThreadDelay (Time 1000000000s))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 2) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventFollowControl (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventAwaitControl (RacyThreadId [4],1) (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing EventThreadSleep) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventDeschedule Sleep)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing EventThreadWake) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventPerformAction (RacyThreadId [3],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 3) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventPerformAction (RacyThreadId [3],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventTxCommitted [Labelled (TVarId 0) Nothing] [] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [TVarId 0], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventPerformAction (RacyThreadId [2],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 4) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventPerformAction (RacyThreadId [2],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventPerformAction (RacyThreadId [1],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 5) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventPerformAction (RacyThreadId [1],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],2)] []))) 
      Assertion failed
      CallStack (from HasCallStack):
        assert, called at src/Control/Monad/IOSimPOR/Internal.hs:990:5 in io-sim-0.4.0.0-inplace:Control.Monad.IOSimPOR.Internal
      Use --quickcheck-replay=898967 to reproduce.
      Use -p '/propExploration/' to rerun this test only.

    propExploration:                           FAIL (44.78s)
      *** Failed! (after 66 tests and 44 shrinks):
      Exception:
        Assertion failed
        CallStack (from HasCallStack):
          assert, called at src\Control\Monad\IOSimPOR\Internal.hs:989:5 in io-sim-0.4.0.0-inplace:Control.Monad.IOSimPOR.Internal
      Tasks [Task [],Task [ThrowTo 4],Task [WhenSet 19 18,ThrowTo 0],Task [WhenSet 18 0,ThrowTo 2],Task [WhenSet 0 0]]
      Schedule control: ControlAwait [ScheduleMod (RacyThreadId [5],2) ControlDefault [(RacyThreadId [4],2),(RacyThreadId [3],2),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)]]
      RacyThreadId [4] delayed at time Time 0s
        until after:
          RacyThreadId [5]
      
      Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventSimStart (ControlAwait [ScheduleMod (RacyThreadId [5],2) ControlDefault [(RacyThreadId [4],2),(RacyThreadId [3],2),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)]]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventTxCommitted [] [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventTxCommitted [] [Labelled (TVarId 1) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventThreadForked (RacyThreadId [1]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventThreadForked (RacyThreadId [2]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventThreadForked (RacyThreadId [3]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventThreadForked (RacyThreadId [4]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventThreadForked (RacyThreadId [5]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventTxCommitted [Labelled (TVarId 1) Nothing] [] (Just (Effect {effectReads = fromList [], effectWrites = fromList [TVarId 1], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 8 (Just "main") (EventThreadDelay (Time 1000000000s))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 2) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 3) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 4) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventTxCommitted [Labelled (TVarId 0) Nothing] [] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [TVarId 0], effectForks = fromList [], effectThrows = [], effectWakeup = [RacyThreadId [5],RacyThreadId [4]], effectStatusReads = [], effectStatusWrites = [RacyThreadId [5],RacyThreadId [4]]})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 1 Nothing (EventTxWakeup [Labelled (TVarId 0) Nothing])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventTxWakeup [Labelled (TVarId 0) Nothing])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventUnblocked [RacyThreadId [5],RacyThreadId [4]])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 2 Nothing (EventFollowControl (ControlAwait [ScheduleMod (RacyThreadId [5],2) ControlDefault [(RacyThreadId [4],2),(RacyThreadId [3],2),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)]]))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 2 Nothing (EventAwaitControl (RacyThreadId [5],2) (ControlFollow [(RacyThreadId [4],2),(RacyThreadId [3],2),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing EventThreadSleep) (Cons (SimPOREvent (Time 0s) (RacyThreadId [5]) 2 Nothing (EventDeschedule Sleep)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing EventThreadWake) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing (EventReschedule (ControlFollow [(RacyThreadId [4],2),(RacyThreadId [3],2),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing (EventPerformAction (RacyThreadId [4],2))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing (EventTxCommitted [Labelled (TVarId 0) Nothing] [] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [TVarId 0], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 2 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 2 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],2),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 2 Nothing (EventPerformAction (RacyThreadId [3],2))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 2 Nothing (EventThrowTo (ExitFailure 0) (RacyThreadId [1]))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventPerformAction (RacyThreadId [2],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 5) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],1)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventPerformAction (RacyThreadId [1],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventThrow (ExitFailure 0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventThreadUnhandled (ExitFailure 0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventDeschedule (Terminated FinishedDied))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],1),(RacyThreadId [2],1)] []))) 
      Assertion failed
      CallStack (from HasCallStack):
        assert, called at src\Control\Monad\IOSimPOR\Internal.hs:989:5 in io-sim-0.4.0.0-inplace:Control.Monad.IOSimPOR.Internal
      Use --quickcheck-replay=721896 to reproduce.
      Use -p '/propExploration/' to rerun this test only.

[jorisdral]

Found another https://github.com/input-output-hk/io-sim/actions/runs/4535458588/jobs/7990928953?pr=72

[bolt12]

until after:
  RacyThreadId [4]
      
  Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventSimStart (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventTxCommitted [] [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventTxCommitted [] [Labelled (TVarId 1) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventThreadForked (RacyThreadId [1]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventThreadForked (RacyThreadId [2]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventThreadForked (RacyThreadId [3]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventThreadForked (RacyThreadId [4]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventTxCommitted [Labelled (TVarId 1) Nothing] [] (Just (Effect {effectReads = fromList [], effectWrites = fromList [TVarId 1], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventThreadDelay (Time 1000000000s))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 2) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventFollowControl (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventAwaitControl (RacyThreadId [4],1) (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing EventThreadSleep) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventDeschedule Sleep)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing EventThreadWake) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventPerformAction (RacyThreadId [3],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 3) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventPerformAction (RacyThreadId [3],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventTxCommitted [Labelled (TVarId 0) Nothing] [] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [TVarId 0], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventPerformAction (RacyThreadId [2],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 4) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventPerformAction (RacyThreadId [2],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventPerformAction (RacyThreadId [1],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 5) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventPerformAction (RacyThreadId [1],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],2)] []))) 
  Assertion failed
  CallStack (from HasCallStack):
    assert, called at src/Control/Monad/IOSimPOR/Internal.hs:990:5 in io-sim-0.4.0.0-inplace:Control.Monad.IOSimPOR.Internal
  Use --quickcheck-replay=406601 to reproduce.
  Use -p '/propExploration/' to rerun this test only.

[coot]

@bolt12 found the regression was introduced in 669d6b2

[bolt12]

Specifically this line:

io-sim/io-sim/src/Control/Monad/IOSimPOR/Internal.hs

Line 840 in 669d6b2

let thread1 = thread { threadBlocked = True , threadEffect = effect <> statusWriteEffect tid }

[bolt12]

All seeds get fixed by altering the line above, except @jorisdral 's which seem to require to comment out a different set of the lines that add the statusWriteEffect. This means that the introduction of these effects can lead to the generation of unstable schedules that break the tests. Fixing just these lines won't do because there's still chance for the bug to exist. I still haven't found the root cause nor a way to easily fix the issue.

Edit: Interestingly the set of lines that need change are disjoint, which means this is small change results in very arbitrary consequences.

[bolt12]

Just leaving this for future record. If I fix the issue with writeStatusEffect we get new test failures, like:

propExploration: FAIL (14.00s)
*** Failed! (after 33 tests and 37 shrinks):
Exception:
Assertion failed
CallStack (from HasCallStack):
assert, called at src/Control/Monad/IOSimPOR/Internal.hs:990:5 in io-sim-0.5.0.0-inplace:Control.Monad.IOSimPOR.Internal
Tasks [Task [WhenSet 4 0],Task [WhenSet 0 0],Task [WhenSet 5 5,WhenSet 5 4],Task [CheckStatus 0,WhenSet 0 0]]
Schedule control: ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)]]
RacyThreadId [3] delayed at time Time 0s
until after:
RacyThreadId [1]
RacyThreadId [2]

Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventSimStart (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)]]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventTxCommitted [] [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventTxCommitted [] [Labelled (TVarId 1) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventThreadForked (RacyThreadId [1]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventThreadForked (RacyThreadId [2]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventThreadForked (RacyThreadId [3]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventThreadForked (RacyThreadId [4]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventTxCommitted [Labelled (TVarId 1) Nothing] [] (Just (Effect {effectReads = fromList [], effectWrites = fromList [TVarId 1], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventThreadDelay (Time 1000000000s))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 2) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time0s) (RacyThreadId [4]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventFollowControl (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)]]))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventAwaitControl (RacyThreadId [4],1) (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventDeschedule Sleep)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventPerformAction (RacyThreadId [3],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 3) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s)(RacyThreadId [3]) 1 Nothing EventThreadSleep) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],0),(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventPerformAction (RacyThreadId [2],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 4) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],0),(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventPerformAction (RacyThreadId [1],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 5) Nothing] (Just (Effect {effectReads = fromList [TVarId1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],1),(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventPerformAction (RacyThreadId [2],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing EventThreadWake) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],1),(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventPerformAction (RacyThreadId [3],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventTxCommitted [Labelled (TVarId 0) Nothing] [] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [TVarId 0], effectForks = fromList [], effectThrows = [], effectWakeup = [RacyThreadId [2]], effectStatusReads = [], effectStatusWrites = [RacyThreadId [2]]})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventTxWakeup [Labelled (TVarId 0) Nothing])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventUnblocked [RacyThreadId [2]])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],2),(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventPerformAction (RacyThreadId [2],2))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],1),(RacyThreadId [2],3)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventPerformAction (RacyThreadId [1],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventDeschedule Blocked)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 3 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],3)] [])))
Assertion failed
CallStack (from HasCallStack):
assert, called at src/Control/Monad/IOSimPOR/Internal.hs:990:5 in io-sim-0.5.0.0-inplace:Control.Monad.IOSimPOR.Internal
Use --quickcheck-replay=406601 to reproduce.

The reason is because there's this function onlyReadEffects that forgets to check statusReadEffects.

[coot]

And another one here:

    propExploration:                           FAIL (11.10s)
      *** Failed! (after 15 tests and 32 shrinks):
      Exception:
        Assertion failed
        CallStack (from HasCallStack):
          assert, called at src\\Control\\Monad\\IOSimPOR\\Internal.hs:1010:5 in io-sim-0.6.0.0-inplace:Control.Monad.IOSimPOR.Internal
      Tasks [Task [WhenSet 3 0],Task [WhenSet 0 0],Task [WhenSet 4 4,WhenSet 4 3],Task [WhenSet 0 0]]
      Schedule control: ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]
      RacyThreadId [3] delayed at time Time 0s
        until after:
          RacyThreadId [4]
      
      Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventSimStart (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventTxCommitted [] [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 0 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventTxCommitted [] [Labelled (TVarId 1) Nothing] (Just (Effect {effectReads = fromList [], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 1 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventThreadForked (RacyThreadId [1]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 2 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventThreadForked (RacyThreadId [2]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 3 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventThreadForked (RacyThreadId [3]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 4 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventThreadForked (RacyThreadId [4]))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 5 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventTxCommitted [Labelled (TVarId 1) Nothing] [] (Just (Effect {effectReads = fromList [], effectWrites = fromList [TVarId 1], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (ThreadId []) 6 (Just "main") (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (ThreadId []) 7 (Just "main") (EventThreadDelay (TimeoutId 0) (Time 1000000000s))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 2) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventFollowControl (ControlAwait [ScheduleMod (RacyThreadId [4],1) ControlDefault [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)]]))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventAwaitControl (RacyThreadId [4],1) (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing EventThreadSleep) (Cons (SimPOREvent (Time 0s) (RacyThreadId [4]) 1 Nothing (EventDeschedule Sleep)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing EventThreadWake) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],0),(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventPerformAction (RacyThreadId [3],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 3) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [3],1),(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventPerformAction (RacyThreadId [3],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventTxCommitted [Labelled (TVarId 0) Nothing] [] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [TVarId 0], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [3]) 1 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],0),(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventPerformAction (RacyThreadId [2],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 4) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],1),(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventPerformAction (RacyThreadId [2],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 1 Nothing (EventDeschedule (Blocked BlockedOnSTM))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],0),(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventPerformAction (RacyThreadId [1],0))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventTxCommitted [] [Labelled (TVarId 5) Nothing] (Just (Effect {effectReads = fromList [TVarId 1], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventUnblocked [])) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 0 Nothing (EventDeschedule Yield)) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventReschedule (ControlFollow [(RacyThreadId [1],1),(RacyThreadId [2],2)] []))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventPerformAction (RacyThreadId [1],1))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventTxBlocked [Labelled (TVarId 0) Nothing] (Just (Effect {effectReads = fromList [TVarId 0], effectWrites = fromList [], effectForks = fromList [], effectThrows = [], effectWakeup = [], effectStatusReads = [], effectStatusWrites = []})))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [1]) 1 Nothing (EventDeschedule (Blocked BlockedOnSTM))) (Cons (SimPOREvent (Time 0s) (RacyThreadId [2]) 2 Nothing (EventReschedule (ControlFollow [(RacyThreadId [2],2)] []))) 
      Assertion failed
      CallStack (from HasCallStack):
        assert, called at src\\Control\\Monad\\IOSimPOR\\Internal.hs:1010:5 in io-sim-0.6.0.0-inplace:Control.Monad.IOSimPOR.Internal
      Use --quickcheck-replay=377878 to reproduce.
      Use -p '/propExploration/' to rerun this test only.

[coot]

We removed threadStatus.