Error trying modelingtoolkitize for single equation ODE

[ricfrod]

Hello! I've been dabbling with ModelingToolkit.jl for a few days and was putting together a presentation for my thesis advisors when I encountered this error:

f(x,p,t) = 0.98x
x0 = 1.0
tspan = (0.0,1.0)
prob = ODEProblem(f,x0,tspan)
sys = modelingtoolkitize(prob)

MethodError: no method matching similar(::Float64, ::Type{Num})
Closest candidates are:
  similar(::Union{LinearAlgebra.Adjoint{T, var"#s832"}, LinearAlgebra.Transpose{T, var"#s832"}} where {T, var"#s832"<:(AbstractVector{T} where T)}, ::Type{T}) where T at C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.6\LinearAlgebra\src\adjtrans.jl:230
  similar(::Union{LinearAlgebra.Adjoint{T, S}, LinearAlgebra.Transpose{T, S}} where {T, S}, ::Type{T}) where T at C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.6\LinearAlgebra\src\adjtrans.jl:234
  similar(::Union{LinearAlgebra.Adjoint{T, S}, LinearAlgebra.Transpose{T, S}} where {T, S}, ::Type{T}, ::Tuple{Vararg{Int64, N}}) where {T, N} at C:\buildbot\worker\package_win64\build\usr\share\julia\stdlib\v1.6\LinearAlgebra\src\adjtrans.jl:235
  ...

I know it's a simple system, but I was surprised to find this problem. Other attempts for systems of multiple ODEs worked fine before this. Am I missing something?

Thanks in advance!

[ChrisRackauckas]

The scalar case needs some special casing: #1005

[ricfrod]

Thank you Chris!