fix JuliaLang/julia#40337, no error info from serialized TaskFailedException (JuliaLang/julia#40395)

Author: JeffBezanson

src/clusterserialize.jl

@@ -102,19 +102,6 @@ function serialize(s::ClusterSerializer, t::Core.TypeName)
     nothing
 end
 
-function serialize(s::ClusterSerializer, t::Task)
-    serialize_cycle(s, t) && return
-    if istaskstarted(t) && !istaskdone(t)
-        error("cannot serialize a running Task")
-    end
-    writetag(s.io, TASK_TAG)
-    serialize(s, t.code)
-    serialize(s, t.storage)
-    serialize(s, t._state)
-    serialize(s, t.result)
-    serialize(s, t._isexception)
-end
-
 function serialize(s::ClusterSerializer, g::GlobalRef)
     # Record if required and then invoke the default GlobalRef serializer.
     sym = g.name
@@ -244,17 +231,6 @@ function deserialize(s::ClusterSerializer, t::Type{<:CapturedException})
     return CapturedException(capex, bt)
 end
 
-function deserialize(s::ClusterSerializer, ::Type{Task})
-    t = Task(nothing)
-    deserialize_cycle(s, t)
-    t.code = deserialize(s)
-    t.storage = deserialize(s)
-    t._state = deserialize(s)::UInt8
-    t.result = deserialize(s)
-    t._isexception = deserialize(s)
-    t
-end
-
 """
     clear!(syms, pids=workers(); mod=Main)
 

test/distributed_exec.jl

@@ -1675,7 +1675,7 @@ let e = @test_throws RemoteException pmap(1) do _
     es = sprint(showerror, e.value)
     @test contains(es, ":\nTaskFailedException\nStacktrace:\n")
     @test contains(es, "\n\n    nested task error:")
-    @test_broken contains(es, "\n\n    nested task error: 42\n")
+    @test contains(es, "\n\n    nested task error: 42\n")
 end
 
 # issue #27429, propagate relative `include` path to workers