fwiw, i also get a warning message when using DiffEqGPU which complains about incremental compilation not working:
┌ Info: Recompiling stale cache file /home/bq_nbecker/isi/julia_pkg/GPUTest/compiled/v1.2/DiffEqGPU/8rwkT.ji for DiffEqGPU [071ae1c0-96b5-11e9-1965-c90190d839ea]
└ @ Base loading.jl:1240
WARNING: Method definition overdub(Cassette.Context{N, M, T, P, B, H} where H<:Union{Cassette.DisableHooks, Nothing} where B<:Union{Nothing, Base.IdDict{Module, Base.Dict{Symbol, Cassette.BindingMeta}}} where P<:Cassette.AbstractPass where T<:Union{Nothing, Cassette.Tag{N, X, E} where E where X where N<:Cassette.AbstractContextName} where M where N<:Cassette.AbstractContextName, Any...) in module Cassette at /home/bq_nbecker/isi/julia_pkg/GPUTest/packages/Cassette/YCOeN/src/overdub.jl:524 overwritten in module GPUifyLoops at /home/bq_nbecker/isi/julia_pkg/GPUTest/packages/Cassette/YCOeN/src/overdub.jl:524.
** incremental compilation may be fatally broken for this module **