no method matching `isconstant(::DynamicPolynomials.Polynomial)`

[baggepinnen]

using ModelingToolkit, LinearAlgebra
@variables x[1:4] u 
x = collect(x)
ex = Num[0.01x[3] + x[1], 0.01x[4] + x[2], (0.0005u + 5.000000000000001e-5(x[4]^2)*sin(x[2]) + 0.0009810000000000003cos(x[2])*sin(x[2])) / (0.06 - 0.010000000000000002(cos(x[2])^2)) + x[3], (0.001(-u - 0.1(x[4]^2)*sin(x[2]))*cos(x[2]) - 0.011772000000000001sin(x[2])) / (0.06 - 0.010000000000000002(cos(x[2])^2)) + x[4]]
dot(ex, randn(4,4), ex)

results in

ERROR: LoadError: MethodError: no method matching isconstant(::DynamicPolynomials.Polynomial{true, Float64})
Closest candidates are:
  isconstant(::MultivariatePolynomials.AbstractVariable) at ~/.julia/packages/MultivariatePolynomials/0oEYT/src/monomial.jl:90
  isconstant(::MultivariatePolynomials.AbstractTermLike) at ~/.julia/packages/MultivariatePolynomials/0oEYT/src/monomial.jl:89
Stacktrace:
  [1] (PolyForm{Real})(p::DynamicPolynomials.Polynomial{true, Float64}, d1::Bijections.Bijection{Any, Any}, d2::Dict{Sym, Any}, m::Nothing)
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:39
  [2] PolyForm(x::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}, pvar2sym::Bijections.Bijection{Any, Any}, sym2term::Dict{Sym, Any}, vtype::Type; Fs::Type, recurse::Bool, metadata::Nothing)
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:169
  [3] expand(expr::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing})
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:232
  [4] (::ComposedFunction{typeof(SymbolicUtils._iszero), typeof(expand)})(x::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}; kw::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Base ./operators.jl:1085
  [5] ComposedFunction
    @ ./operators.jl:1085 [inlined]
  [6] _any(f::ComposedFunction{typeof(SymbolicUtils._iszero), typeof(expand)}, itr::Vector{SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}}, #unused#::Colon)
    @ Base ./reduce.jl:1110
  [7] any(f::Function, a::Vector{SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}}; dims::Function)
    @ Base ./reducedim.jl:899
  [8] any(f::Function, a::Vector{SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}})
    @ Base ./reducedim.jl:899
  [9] fraction_iszero(x::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing})
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:327
 [10] iszero(x::Num)
    @ Symbolics ~/.julia/packages/Symbolics/LTmGT/src/num.jl:91
 [11] dot(x::Vector{Num}, A::Matrix{Float64}, y::Vector{Num})
    @ LinearAlgebra ~/julia-1.7.0-rc2/share/julia/stdlib/v1.7/LinearAlgebra/src/generic.jl:958
 [12] top-level scope
    @ ~/.julia/dev/JuliaSimControls/test/symbolic_mpc.jl:89
in expression starting at /home/fredrikb/.julia/dev/JuliaSimControls/test/symbolic_mpc.jl:89

[baggepinnen]

Actually, this error appears still on the latest versions of Symbolics and SymbolicUtils, but in a different context

using Symbolics, LinearAlgebra
using SparseArrays
nx = 2
ny = 1
nu = 1
N = 20
U0 = randn(nu, N)
#G = c2d(ss(tf(1, [1, 0.1, 1])), 0.1)
#res = lsim(G, U0)
#Y0 = res.y
Y0 = randn(ny, N)

nx = 2
ny = 1
nu = 1

@variables A[1:nx, 1:nx] B[1:nx, 1:nu] C[1:ny, 1:nx] D[1:ny, 1:nu] K[1:nx, 1:ny]
A,B,C,D,K = collect.((A,B,C,D,K))
##
next = []
w = []
x = @variables x1[1:nx]
x = collect(x[])
push!(w, x)
U = []
Y = []
i = 1
c = 0
for i = 1:N
    global x, c
    un = Symbol("u$i")
    u = @variables $un[1:nu]
    u = collect(u[])

    yn = Symbol("y$i")
    y = @variables $yn[1:ny]
    y = collect(y[])
    yh = C*x + D*u
    e = y-yh
    c += sum(abs2, e)

    xp = A*x + B*u + K*e
    xn = Symbol("x$(i+1)")
    x = @variables $xn[1:nx]
    x = collect(x[])
    push!(next, xp)
    push!(w, x)
    push!(U, u)
    push!(Y, y)
end

##
@variables λ[1:N*nx]
λ = collect(λ)
@variables σ
# vcollect(x) = reduce(vcat, collect.(x))
vcollect(x) = reduce(vcat, x)

next2 = vcollect(next)
w2 = vcollect(w)
g = next2 .- w2[nx+1:end]
p = vcollect(vec.((A,B,C,D,K)))
w3 = [p; w2]
wλ = [w3; λ]
lagrange = σ*c + λ'g

grad = Symbolics.gradient(c, w3);
jac = Symbolics.sparsejacobian(g, w3);
# hess = Symbolics.sparsehessian(c, w3) # errors, workaround below
laghess = Symbolics.sparsejacobian(Symbolics.gradient(lagrange, wλ), wλ)
laghess = tril(laghess)

w0 = randn(size(w3))
U2 = vcollect(U)
Y2 = vcollect(Y)
λ0 = randn(size(λ))

@time jacfun     = build_function(jac, w3, U2, expression=Val{false}()) # this errors

julia> jacfun     = build_function(jac, w3, U2, expression=Val{false}())
ERROR: MethodError: no method matching isconstant(::DynamicPolynomials.Polynomial{true, Int64})
Closest candidates are:
  isconstant(::MultivariatePolynomials.AbstractVariable) at ~/.julia/packages/MultivariatePolynomials/0oEYT/src/monomial.jl:90
  isconstant(::MultivariatePolynomials.AbstractTermLike) at ~/.julia/packages/MultivariatePolynomials/0oEYT/src/monomial.jl:89
Stacktrace:
  [1] (PolyForm{Real})(p::DynamicPolynomials.Polynomial{true, Int64}, d1::Bijections.Bijection{Any, Any}, d2::Dict{SymbolicUtils.Sym, Any}, m::Nothing)
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:39
  [2] PolyForm(x::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}, pvar2sym::Bijections.Bijection{Any, Any}, sym2term::Dict{SymbolicUtils.Sym, Any}, vtype::Type; Fs::Type, recurse::Bool, metadata::Nothing)
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:169
  [3] expand(expr::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing})
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:232
  [4] (::ComposedFunction{typeof(SymbolicUtils._iszero), typeof(expand)})(x::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}; kw::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Base ./operators.jl:1085
  [5] ComposedFunction
    @ ./operators.jl:1085 [inlined]
  [6] _any(f::ComposedFunction{typeof(SymbolicUtils._iszero), typeof(expand)}, itr::Vector{SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}}, #unused#::Colon)
    @ Base ./reduce.jl:1110
  [7] any(f::Function, a::Vector{SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}}; dims::Function)
    @ Base ./reducedim.jl:899
  [8] any(f::Function, a::Vector{SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing}})
    @ Base ./reducedim.jl:899
  [9] fraction_iszero(x::SymbolicUtils.Add{Real, Int64, Dict{Any, Number}, Nothing})
    @ SymbolicUtils ~/.julia/packages/SymbolicUtils/fgHzN/src/polyform.jl:327
 [10] iszero(x::Num)
    @ Symbolics ~/.julia/packages/Symbolics/LTmGT/src/num.jl:91
 [11] _iszero
    @ ~/julia-1.7.0-rc3/share/julia/stdlib/v1.7/SparseArrays/src/higherorderfns.jl:207 [inlined]
 [12] _map_zeropres!(f::Symbolics.var"#266#267"{Symbol}, C::SparseMatrixCSC{Num, Int64}, A::SparseMatrixCSC{Num, Int64})
    @ SparseArrays.HigherOrderFns ~/julia-1.7.0-rc3/share/julia/stdlib/v1.7/SparseArrays/src/higherorderfns.jl:248
 [13] _noshapecheck_map(::Symbolics.var"#266#267"{Symbol}, ::SparseMatrixCSC{Num, Int64})
    @ SparseArrays.HigherOrderFns ~/julia-1.7.0-rc3/share/julia/stdlib/v1.7/SparseArrays/src/higherorderfns.jl:171
 [14] map
    @ ~/julia-1.7.0-rc3/share/julia/stdlib/v1.7/SparseArrays/src/higherorderfns.jl:1162 [inlined]
 [15] _make_array
    @ ~/.julia/packages/Symbolics/LTmGT/src/build_function.jl:269 [inlined]
 [16] make_array(s::Symbolics.SerialForm, dargs::Vector{SymbolicUtils.Code.DestructuredArgs}, arr::SparseMatrixCSC{Num, Int64}, similarto::Symbol)
    @ Symbolics ~/.julia/packages/Symbolics/LTmGT/src/build_function.jl:229
 [17] _build_function(::Symbolics.JuliaTarget, ::SparseMatrixCSC{Num, Int64}, ::Vector{Num}, ::Vararg{Vector{Num}}; expression::Val{false}, expression_module::Module, checkbounds::Bool, postprocess_fbody::Symbolics.var"#257#261", linenumbers::Bool, outputidxs::Nothing, skipzeros::Bool, wrap_code::Tuple{Nothing, Nothing}, fillzeros::Bool, parallel::Symbolics.SerialForm, kwargs::Base.Pairs{Symbol, Union{}, Tuple{}, NamedTuple{(), Tuple{}}})
    @ Symbolics ~/.julia/packages/Symbolics/LTmGT/src/build_function.jl:194
 [18] build_function(::SparseMatrixCSC{Num, Int64}, ::Vararg{Any}; target::Symbolics.JuliaTarget, kwargs::Base.Pairs{Symbol, Val{false}, Tuple{Symbol}, NamedTuple{(:expression,), Tuple{Val{false}}}})
    @ Symbolics ~/.julia/packages/Symbolics/LTmGT/src/build_function.jl:52
 [19] top-level scope
    @ ./timing.jl:220 [inlined]
 [20] top-level scope
    @ ./REPL[3]:0

[judober]

I get a similar error with

MethodError: no method matching isconstant(::DynamicPolynomials.Polynomial{true, Float64})

However, I cannont reproduce it reliable. I occurs in the tests of my package but not when I run it directly from the repl. I tried your example as well and it worked fine from the repl but not from the environment of my package where I get

ERROR: MethodError: no method matching isconstant(::DynamicPolynomials.Polynomial{true, Int64})

But I was not able yet to reproducte this error in a new environment.

Update: I removed some unused dependencies from the package and updated the others. Now it seems to work. Sorry that I cannot be more specific