T8726 fails with Core Lint failure

With !1731 (closed) T8726 fails in the profasm and profthreaded ways with a Core Lint failure in a debugged compiler:

*** Core Lint errors : in result of Tidy Core ***
<no location info>: warning:
    idArity 1 exceeds arity imposed by the strictness signature b: $j_s6cD
    In the RHS of main27 :: [(Integer, Integer)]
                            -> State# RealWorld -> (# State# RealWorld, () #)
    In the body of lambda with binder ds_a4d5 :: [(Integer, Integer)]
    In the body of lambda with binder eta1_X2S :: State# RealWorld
    In a case alternative: (: y_a4da :: (Integer, Integer),
                              ys_a4db :: [(Integer, Integer)])
    In a case alternative: ((,) n1_a31m :: Integer, d_a31n :: Integer)
    In the body of letrec with binders lvl36_s69r :: [Char]
    In the expression: (scctick<main.\.check>
                        join {
                          $j_s6cD [Dmd=<L,1*C1(U(U,A))>]
                            :: State# RealWorld -> (# State# RealWorld, () #)
                          [LclId[JoinId(0)], Arity=1, Str=b, Unf=OtherCon []]
                          $j_s6cD
                            = \ (eta2_a4nZ [OS=OneShot] :: State# RealWorld) ->
                                lvl26_r6Hq eta2_a4nZ lvl36_s69r } in
                        case scctick<prop_rem0> geInteger# n1_a31m main2 of {
                          __DEFAULT ->
                            case scc<prop_rem0> eqInteger# d_a31n main2 of {
                              __DEFAULT ->
                                case scc<prop_rem0>
                                     let {
                                       eta2_s67e [Dmd=<S,U>] :: Integer
                                       [LclId]
                                       eta2_s67e = remInteger n1_a31m d_a31n } in
                                     let {
                                       eta3_s67d [Dmd=<S,U>] :: Integer
                                       [LclId]
                                       eta3_s67d = negateInteger (absInteger d_a31n) } in
                                     scctick<prop_rem0.inside>
                                     case ltInteger# eta3_s67d eta2_s67e of {
                                       __DEFAULT -> False;
                                       1# ->
                                         case ltInteger# eta2_s67e main24 of wild5_X4gd
                                         { __DEFAULT ->
                                         tagToEnum# @ Bool wild5_X4gd
                                         }
                                     }
                                of {
                                  False -> jump $j_s6cD;
                                  True -> lvl33_r6Hx
                                };
                              1# -> case divZeroError of wild4_00 { }
                            };
                          1# ->
                            case scc<prop_rem0> eqInteger# d_a31n main2 of {
                              __DEFAULT ->
                                case scc<prop_rem0>
                                     let {
                                       eta2_s67k [Dmd=<S,U>] :: Integer
                                       [LclId]
                                       eta2_s67k = remInteger n1_a31m d_a31n } in
                                     let {
                                       eta3_s67i :: Integer
                                       [LclId]
                                       eta3_s67i = absInteger d_a31n } in
                                     scctick<prop_rem0.inside>
                                     case ltInteger# eta_r6GX eta2_s67k of {
                                       __DEFAULT -> False;
                                       1# -> ltInteger eta2_s67k eta3_s67i
                                     }
                                of {
                                  False -> jump $j_s6cD;
                                  True -> lvl33_r6Hx
                                };
                              1# -> case divZeroError of wild4_00 { }
                            }
                        })
                         eta1_X2S
    In the RHS of $j_s6cD :: State# RealWorld
                             -> (# State# RealWorld, () #)
*** Offending Program ***