Strange behavior of saveat (MWE)

General Usage
1

I am trying to put save related arguments in a namedtuple. Here is my experiment.

using DifferentialEquations

function exponen!(du, u, param, t)
	du[1] = -u[1]
end

prob = ODEProblem(exponen!, [2.], tspan)
# This works as expected
solve(prob, Tsit5(), saveat=[0.2, 1.3], save_start=true, save_end=true)


saveat = (saveat=[0.2, 1.3], save_start=true, save_end=true)
solve(prob, Tsit5(), saveat...)   ### Generates an error

I do not understand why the two approaches are not identical. Thanks!

Here is the error:

ERROR: MethodError: Cannot `convert` an object of type Float64 to an object of type Vector{Float64}
Closest candidates are:
  convert(::Type{Vector{T}}, ::SubArray{T, 1, Base.ReshapedArray{T, 1, BandedMatrices.BandedMatrix{T}, Tuple{Base.MultiplicativeInverses.SignedMultiplicativeInverse{Int64}}}, Tuple{BandedMatrices.BandSlice}, false} where T) where T at ~/.julia/packages/BandedMatrices/nTq9x/src/banded/BandedMatrix.jl:395
  convert(::Type{T}, ::Union{Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}} where T, Union{Base.LogicalIndex{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, Base.ReinterpretArray{T, N, <:Any, <:Union{SubArray{<:Any, <:Any, var"#s14"}, var"#s14"}} where var"#s14"<:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}, Base.ReshapedArray{T, N, <:Union{Base.ReinterpretArray{<:Any, <:Any, <:Any, <:Union{SubArray{<:Any, <:Any, var"#s15"}, var"#s15"}}, SubArray{<:Any, <:Any, var"#s15"}, var"#s15"}} where var"#s15"<:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}, SubArray{T, N, <:Union{Base.ReinterpretArray{<:Any, <:Any, <:Any, <:Union{SubArray{<:Any, <:Any, var"#s16"}, var"#s16"}}, Base.ReshapedArray{<:Any, <:Any, <:Union{Base.ReinterpretArray{<:Any, <:Any, <:Any, <:Union{SubArray{<:Any, <:Any, var"#s16"}, var"#s16"}}, SubArray{<:Any, <:Any, var"#s16"}, var"#s16"}}, var"#s16"}} where var"#s16"<:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}, Adjoint{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, Diagonal{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, LowerTriangular{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, Symmetric{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, Transpose{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, Tridiagonal{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, UnitLowerTriangular{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, UnitUpperTriangular{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, UpperTriangular{T, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}, PermutedDimsArray{T, N, <:Any, <:Any, <:Union{NNlib.BatchedAdjoint{T, <:CUDA.CuArray{T}}, NNlib.BatchedTranspose{T, <:CUDA.CuArray{T}}}}} where {T, N}}) where T<:Array at ~/.julia/packages/NNlibCUDA/kCpTE/src/batchedadjtrans.jl:15
  convert(::Type{<:Array}, ::LabelledArrays.LArray) at ~/.julia/packages/LabelledArrays/IYs8M/src/larray.jl:143
  ...
Stacktrace:
  [1] setindex!(A::Vector{Vector{Float64}}, x::Float64, i1::Int64)
    @ Base ./array.jl:966
  [2] _unsafe_copyto!(dest::Vector{Vector{Float64}}, doffs::Int64, src::Vector{Float64}, soffs::Int64, n::Int64)
    @ Base ./array.jl:253
  [3] unsafe_copyto!
    @ ./array.jl:307 [inlined]
  [4] _copyto_impl!
    @ ./array.jl:331 [inlined]
  [5] copyto!
    @ ./array.jl:317 [inlined]
  [6] copyto!
    @ ./array.jl:343 [inlined]
  [7] copyto_axcheck!
    @ ./abstractarray.jl:1127 [inlined]
  [8] Array
    @ ./array.jl:626 [inlined]
  [9] convert
    @ ./array.jl:617 [inlined]
 [10] __init(prob::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, alg::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, timeseries_init::Vector{Float64}, ts_init::Bool, ks_init::Bool, recompile::Type{Val{true}}; saveat::Tuple{}, tstops::Tuple{}, d_discontinuities::Tuple{}, save_idxs::Nothing, save_everystep::Bool, save_on::Bool, save_start::Bool, save_end::Nothing, callback::Nothing, dense::Bool, calck::Bool, dt::Float32, dtmin::Nothing, dtmax::Float32, force_dtmin::Bool, adaptive::Bool, gamma::Rational{Int64}, abstol::Nothing, reltol::Nothing, qmin::Rational{Int64}, qmax::Int64, qsteady_min::Int64, qsteady_max::Int64, beta1::Nothing, beta2::Nothing, qoldinit::Rational{Int64}, controller::Nothing, fullnormalize::Bool, failfactor::Int64, maxiters::Int64, internalnorm::typeof(DiffEqBase.ODE_DEFAULT_NORM), internalopnorm::typeof(opnorm), isoutofdomain::typeof(DiffEqBase.ODE_DEFAULT_ISOUTOFDOMAIN), unstable_check::typeof(DiffEqBase.ODE_DEFAULT_UNSTABLE_CHECK), verbose::Bool, timeseries_errors::Bool, dense_errors::Bool, advance_to_tstop::Bool, stop_at_next_tstop::Bool, initialize_save::Bool, progress::Bool, progress_steps::Int64, progress_name::String, progress_message::typeof(DiffEqBase.ODE_DEFAULT_PROG_MESSAGE), userdata::Nothing, allow_extrapolation::Bool, initialize_integrator::Bool, alias_u0::Bool, alias_du0::Bool, initializealg::OrdinaryDiffEq.DefaultInit, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/SRiFK/src/solve.jl:247
 [11] __init(prob::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, alg::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, timeseries_init::Vector{Float64}, ts_init::Bool, ks_init::Bool, recompile::Type{Val{true}}) (repeats 2 times)
    @ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/SRiFK/src/solve.jl:10
 [12] __solve(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vector{Float64}, ::Vararg{Any}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/SRiFK/src/solve.jl:5
 [13] __solve(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vector{Float64}, ::Bool, ::Bool)
    @ OrdinaryDiffEq ~/.julia/packages/OrdinaryDiffEq/SRiFK/src/solve.jl:1
 [14] solve_call(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vararg{Any}; merge_callbacks::Bool, kwargshandle::KeywordArgError, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/J8AU0/src/solve.jl:494
 [15] solve_call(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, FunctionWrappersWrappers.FunctionWrappersWrapper{Tuple{FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{Float64}, Vector{Float64}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, Float32}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{Float64}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}, FunctionWrappers.FunctionWrapper{Nothing, Tuple{Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, Vector{ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}, SciMLBase.NullParameters, ForwardDiff.Dual{ForwardDiff.Tag{DiffEqBase.OrdinaryDiffEqTag, Float64}, Float64, 1}}}}, false}, UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vararg{Any})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/J8AU0/src/solve.jl:464
 [16] solve_up(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, typeof(exponen!), UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Nothing, ::Vector{Float64}, ::SciMLBase.NullParameters, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vararg{Any}; kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/J8AU0/src/solve.jl:856
 [17] solve_up(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, typeof(exponen!), UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Nothing, ::Vector{Float64}, ::SciMLBase.NullParameters, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vararg{Any})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/J8AU0/src/solve.jl:829
 [18] solve(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, typeof(exponen!), UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vararg{Any}; sensealg::Nothing, u0::Nothing, p::Nothing, wrap::Val{true}, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/J8AU0/src/solve.jl:823
 [19] solve(::ODEProblem{Vector{Float64}, Tuple{Float32, Float32}, true, SciMLBase.NullParameters, ODEFunction{true, SciMLBase.AutoSpecialize, typeof(exponen!), UniformScaling{Bool}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, typeof(SciMLBase.DEFAULT_OBSERVED), Nothing, Nothing}, Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}}, SciMLBase.StandardODEProblem}, ::Tsit5{typeof(OrdinaryDiffEq.trivial_limiter!), typeof(OrdinaryDiffEq.trivial_limiter!), Static.False}, ::Vector{Float64}, ::Vararg{Any})
    @ DiffEqBase ~/.julia/packages/DiffEqBase/J8AU0/src/solve.jl:813
 [20] top-level scope
    @ ~/src/2022/rude/giesekus/MWE_saveat:11

and my project.toml (single package):

Status `~/src/2022/rude/giesekus/MWE_saveat/Project.toml`
  [0c46a032] DifferentialEquations v7.6.0
2

You need an explicit separation between arguments and keyword arguments when splatting. Try

solve(prob, Tsit5(); saveat...)
1 Like
3

It worked! Thank you.