https://github.com/TuringLang/DynamicPPL.jl/pull/76 modifies behaviours of `assume` and `observe` functions. Some redefinition of these functions in Turing are not yet updated. See https://github.com/TuringLang/DynamicPPL.jl/pull/76#issuecomment-619569810