Program bug is silent for coroutines

[xukai92]

When running a model with programmatically error, samplers like SMC suspends silently without throwing the error.

[xukai92]

Simplest example:

julia> using Turing
julia> @model test(xs) = begin
         print(xs[2])
         x ~ Normal(0, 1)
       end
test (generic function with 2 methods)

julia> mf = test([1])
[ Info:  Assume - `x` is a parameter
test_model (generic function with 4 methods)

julia> sample(mf, SMC(10)) #=> suspend

[trappmartin]

TuringLang/Libtask.jl#7

[yebai]

Fixed by TuringLang/Libtask.jl#29