ODEProblem construction crashing when converted from ReactionSystem

[isaacsas]

On Catalyst master:

repressilator = @reaction_network begin
    hillr(P₃,α,K,n), ∅ --> m₁
    hillr(P₁,α,K,n), ∅ --> m₂
    hillr(P₂,α,K,n), ∅ --> m₃
    (δ,γ), m₁ ↔ ∅
    (δ,γ), m₂ ↔ ∅
    (δ,γ), m₃ ↔ ∅
    β, m₁ --> m₁ + P₁
    β, m₂ --> m₂ + P₂
    β, m₃ --> m₃ + P₃
    μ, P₁ --> ∅
    μ, P₂ --> ∅
    μ, P₃ --> ∅
end α K n δ γ β μ

odesys = convert(ODESystem, repressilator)
p = (.5, 40, 2, log(2)/120, 5e-3, 20*log(2)/120, log(2)/60)
u₀ = [0.,0.,0.,20.,0.,0.]
tspan = (0., 10000.)
oprob = ODEProblem(repressilator, u₀, tspan, p)

works but

u₀map  = Pair.(species(repressilator), u₀)
pmap   = Pair.(params(repressilator), p)
oprob2 = ODEProblem(osys, u₀map, tspan, pmap)

gives the following error

ERROR: ArgumentError: invalid index: nothing of type Nothing
Stacktrace:
 [1] to_index(::Nothing) at ./indices.jl:297
 [2] to_index(::Array{Float64,1}, ::Nothing) at ./indices.jl:274
 [3] to_indices at ./indices.jl:325 [inlined]
 [4] to_indices at ./indices.jl:322 [inlined]
 [5] setindex! at ./abstractarray.jl:1153 [inlined]
 [6] varmap_to_vars(::Array{Pair{Term{Real},Float64},1}, ::Array{Term{Real},1}) at /Users/isaacsas/.julia/packages/ModelingToolkit/tJisO/src/variables.jl:219
 [7] ODEProblem{true,tType,isinplace,P,F,K,PT} where PT where K where F where P where isinplace where tType(::ODESystem, ::Array{Pair{Term{Real},Float64},1}, ::Tuple{Float64,Float64}, ::Array{Pair{Sym{ModelingToolkit.Parameter{Real}},B} where B,1}; version::Nothing, tgrad::Bool, jac::Bool, checkbounds::Bool, sparse::Bool, simplify::Bool, linenumbers::Bool, parallel::ModelingToolkit.SerialForm, eval_expression::Bool, kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /Users/isaacsas/.julia/packages/ModelingToolkit/tJisO/src/systems/diffeqs/abstractodesystem.jl:270
 [8] ODEProblem{true,tType,isinplace,P,F,K,PT} where PT where K where F where P where isinplace where tType(::ODESystem, ::Array{Pair{Term{Real},Float64},1}, ::Tuple{Float64,Float64}, ::Array{Pair{Sym{ModelingToolkit.Parameter{Real}},B} where B,1}) at /Users/isaacsas/.julia/packages/ModelingToolkit/tJisO/src/systems/diffeqs/abstractodesystem.jl:267
 [9] ODEProblem(::ODESystem, ::Array{Pair{Term{Real},Float64},1}, ::Vararg{Any,N} where N; kwargs::Base.Iterators.Pairs{Union{},Union{},Tuple{},NamedTuple{(),Tuple{}}}) at /Users/isaacsas/.julia/packages/ModelingToolkit/tJisO/src/systems/diffeqs/abstractodesystem.jl:240
 [10] ODEProblem(::ODESystem, ::Array{Pair{Term{Real},Float64},1}, ::Vararg{Any,N} where N) at /Users/isaacsas/.julia/packages/ModelingToolkit/tJisO/src/systems/diffeqs/abstractodesystem.jl:240
 [11] top-level scope at REPL[76]:1

[ChrisRackauckas]

somehow the search for the value failed.

[isaacsas]

This is something related to the changes to switch to SymbolicUtils since it was working fine before.

[ChrisRackauckas]

using Catalyst
repressilator = @reaction_network begin
    hillr(P₃,α,K,n), ∅ --> m₁
    hillr(P₁,α,K,n), ∅ --> m₂
    hillr(P₂,α,K,n), ∅ --> m₃
    (δ,γ), m₁ ↔ ∅
    (δ,γ), m₂ ↔ ∅
    (δ,γ), m₃ ↔ ∅
    β, m₁ --> m₁ + P₁
    β, m₂ --> m₂ + P₂
    β, m₃ --> m₃ + P₃
    μ, P₁ --> ∅
    μ, P₂ --> ∅
    μ, P₃ --> ∅
end α K n δ γ β μ

odesys = convert(ODESystem, repressilator)
p = (.5, 40, 2, log(2)/120, 5e-3, 20*log(2)/120, log(2)/60)
u₀ = [0.,0.,0.,20.,0.,0.]
tspan = (0., 10000.)
oprob = ODEProblem(repressilator, u₀, tspan, p)

u₀map  = Pair.(species(repressilator), u₀)
pmap   = Pair.(Catalyst.params(repressilator), p)
oprob2 = ODEProblem(odesys, u₀map, tspan, pmap)

I ran that verbatim and it was fine?

[isaacsas]

Yeah, seems to work now. Not sure if it was something that was fixed in a PR recently, or if I had a polluted REPL. In any case I'll close. Thanks for taking a look!