BoundsError on ModelingToolkit v10.25.0

[icweaver]

Describe the bug 🐞

Hi all, sorry if this was discussed somewhere already, but we seem to be hitting a BoundsError when trying to evaluate an ODEFunction. This only seems to occur when running tests (i.e., with --check-bounds=yes on by default), on ModelingToolkit v10.25.0. Running on ModelingToolkit v9.83.0 looks to work in either check-bounds case. I am super new to working in this ecosystem, so apologies if I am just holding it wrong. Thanks for your time!

Expected behavior

Evaluating the ODEFunction returns a vector, e.g.,

2-element Vector{Float64}:
 0.0
 0.0

based on the MRE below.

Minimal Reproducible Example 👇

Here is a stripped down version of the issue we were seeing over in JuliaAstro:

using ModelingToolkit

import SciMLBase

@independent_variables t
δ = Differential(t)

@variables (u(t))[1:2]
u = Symbolics.scalarize(u)

@parameters p[1:3]
p = Symbolics.scalarize(p)

eqs = [
    δ(u[1]) ~ 0,
    δ(u[2]) ~ 0,
]

sys = complete(System(eqs, t, u, p; name = :Test); split = false)

ODEF = ODEFunction{true, SciMLBase.FullSpecialize}(sys; jac = true)

@info ODEF([3.0, 4.0], [5.0, 6.0, 7.0], NaN)

Running with julia --proj --check-bounds=yes works on ModelingToolkit v9.83.0, but fails with the below error and stacktrace on ModelingToolkit v10.25.0

Error & Stacktrace ⚠️

┌ Error: Exception while generating log record in module Main at /home/mango/Desktop/mtk-10.25.0/modelingtoolkit-mwe.jl:23
│   exception =
│    BoundsError: attempt to access 3-element Vector{Float64} at index [StaticArrays.StaticIndexing{StaticArraysCore.SVector{2, Int64}}([7, 6])]
│    Stacktrace:
│      [1] throw_boundserror(A::Vector{Float64}, I::Tuple{StaticArrays.StaticIndexing{StaticArraysCore.SVector{2, Int64}}})
│        @ Base ./essentials.jl:15
│      [2] checkbounds
│        @ ./abstractarray.jl:699 [inlined]
│      [3] view
│        @ ./subarray.jl:214 [inlined]
│      [4] macro expansion
│        @ ~/.julia/packages/SymbolicUtils/N76BL/src/code.jl:411 [inlined]
│      [5] macro expansion
│        @ ~/.julia/packages/Symbolics/lJiB2/src/build_function.jl:366 [inlined]
│      [6] macro expansion
│        @ ~/.julia/packages/RuntimeGeneratedFunctions/2SjTC/src/RuntimeGeneratedFunctions.jl:161 [inlined]
│      [7] macro expansion
│        @ ./none:0 [inlined]
│      [8] generated_callfunc
│        @ ./none:0 [inlined]
│      [9] (::RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :__mtk_arg_2, :t), ModelingToolkit.var"#_RGF_ModTag", ModelingToolkit.var"#_RGF_ModTag", (0xdecd631f, 0x5fa0b2b7, 0x39c3ec22, 0xe91f5d0b, 0xc1a3c33c), Nothing})(::Vector{Float64}, ::Vector{Float64}, ::Float64)
│        @ RuntimeGeneratedFunctions ~/.julia/packages/RuntimeGeneratedFunctions/2SjTC/src/RuntimeGeneratedFunctions.jl:148
│     [10] macro expansion
│        @ ~/.julia/packages/ModelingToolkit/IdXTK/src/systems/codegen_utils.jl:-1 [inlined]
│     [11] _generated_call
│        @ ~/.julia/packages/ModelingToolkit/IdXTK/src/systems/codegen_utils.jl:353 [inlined]
│     [12] GeneratedFunctionWrapper
│        @ ~/.julia/packages/ModelingToolkit/IdXTK/src/systems/codegen_utils.jl:350 [inlined]
│     [13] (::ODEFunction{true, SciMLBase.FullSpecialize, ModelingToolkit.GeneratedFunctionWrapper{(2, 3, false), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :__mtk_arg_2, :t), ModelingToolkit.var"#_RGF_ModTag", ModelingToolkit.var"#_RGF_ModTag", (0xdecd631f, 0x5fa0b2b7, 0x39c3ec22, 0xe91f5d0b, 0xc1a3c33c), Nothing}, RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:ˍ₋out, :__mtk_arg_1, :__mtk_arg_2, :t), ModelingToolkit.var"#_RGF_ModTag", ModelingToolkit.var"#_RGF_ModTag", (0xacd616fe, 0x3c07c659, 0x027cc8f3, 0x1588f27f, 0x8b9bea8b), Nothing}}, LinearAlgebra.UniformScaling{Bool}, Nothing, Nothing, ModelingToolkit.GeneratedFunctionWrapper{(2, 3, false), RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:__mtk_arg_1, :__mtk_arg_2, :t), ModelingToolkit.var"#_RGF_ModTag", ModelingToolkit.var"#_RGF_ModTag", (0x5e20dbb8, 0x577b73a9, 0x2e64baeb, 0x8651c610, 0x931c41ef), Nothing}, RuntimeGeneratedFunctions.RuntimeGeneratedFunction{(:ˍ₋out, :__mtk_arg_1, :__mtk_arg_2, :t), ModelingToolkit.var"#_RGF_ModTag", ModelingToolkit.var"#_RGF_ModTag", (0x224f4e62, 0x52b2b8de, 0x8b470007, 0x3a5df9fc, 0xb251c427), Nothing}}, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, Nothing, ModelingToolkit.ObservedFunctionCache{System}, Nothing, System, Nothing, Nothing})(u::Vector{Float64}, p::Vector{Float64}, t::Float64)
│        @ SciMLBase ~/.julia/packages/SciMLBase/b4Q81/src/scimlfunctions.jl:2605
│     [14] top-level scope
│        @ ~/Desktop/mtk-10.25.0/modelingtoolkit-mwe.jl:395
│     [15] macro expansion
│        @ logging/logging.jl:385 [inlined]
│     [16] include(mod::Module, _path::String)
│        @ Base ./Base.jl:306
│     [17] exec_options(opts::Base.JLOptions)
│        @ Base ./client.jl:317
│     [18] _start()
│        @ Base ./client.jl:550
└ @ Main ~/Desktop/mtk-10.25.0/modelingtoolkit-mwe.jl:23

Environment (please complete the following information):

• Output of using Pkg; Pkg.status()

Status `~/Desktop/mtk-10.25.0/Project.toml`
  [961ee093] ModelingToolkit v10.25.0
  [0bca4576] SciMLBase v2.121.1

• Output of using Pkg; Pkg.status(; mode = PKGMODE_MANIFEST)

Status `~/Desktop/mtk-10.25.0/Manifest.toml`
  [47edcb42] ADTypes v1.18.0
  [1520ce14] AbstractTrees v0.4.5
  [7d9f7c33] Accessors v0.1.42
  [79e6a3ab] Adapt v4.4.0
  [66dad0bd] AliasTables v1.1.3
  [ec485272] ArnoldiMethod v0.4.0
  [4fba245c] ArrayInterface v7.20.0
  [4c555306] ArrayLayouts v1.12.0
  [e2ed5e7c] Bijections v0.2.2
  [62783981] BitTwiddlingConvenienceFunctions v0.1.6
  [8e7c35d0] BlockArrays v1.7.2
  [70df07ce] BracketingNonlinearSolve v1.5.0
  [2a0fbf3d] CPUSummary v0.2.7
  [d360d2e6] ChainRulesCore v1.26.0
  [fb6a15b2] CloseOpenIntervals v0.1.13
⌅ [861a8166] Combinatorics v1.0.2
  [a80b9123] CommonMark v0.9.1
  [38540f10] CommonSolve v0.2.4
  [bbf7d656] CommonSubexpressions v0.3.1
  [f70d9fcc] CommonWorldInvalidations v1.0.0
  [34da2185] Compat v4.18.1
  [b152e2b5] CompositeTypes v0.1.4
  [a33af91c] CompositionsBase v0.1.2
  [2569d6c7] ConcreteStructs v0.2.3
  [187b0558] ConstructionBase v1.6.0
  [adafc99b] CpuId v0.3.1
  [9a962f9c] DataAPI v1.16.0
  [864edb3b] DataStructures v0.19.1
  [2b5f629d] DiffEqBase v6.190.2
  [459566f4] DiffEqCallbacks v4.10.1
  [77a26b50] DiffEqNoiseProcess v5.24.1
  [163ba53b] DiffResults v1.1.0
  [b552c78f] DiffRules v1.15.1
  [a0c0ee7d] DifferentiationInterface v0.7.9
  [8d63f2c5] DispatchDoctor v0.4.26
  [31c24e10] Distributions v0.25.122
  [ffbed154] DocStringExtensions v0.9.5
  [5b8099bc] DomainSets v0.7.16
  [7c1d4256] DynamicPolynomials v0.6.4
  [06fc5a27] DynamicQuantities v1.10.0
  [4e289a0a] EnumX v1.0.5
  [f151be2c] EnzymeCore v0.8.14
  [e2ba6199] ExprTools v0.1.10
  [55351af7] ExproniconLite v0.10.14
  [7034ab61] FastBroadcast v0.3.5
  [9aa1b823] FastClosures v0.3.2
  [a4df4552] FastPower v1.1.3
  [1a297f60] FillArrays v1.14.0
  [64ca27bc] FindFirstFunctions v1.4.2
  [6a86dc24] FiniteDiff v2.29.0
  [1fa38f19] Format v1.3.7
  [f6369f11] ForwardDiff v1.2.1
  [069b7b12] FunctionWrappers v1.1.3
  [77dc65aa] FunctionWrappersWrappers v0.1.3
  [46192b85] GPUArraysCore v0.2.0
  [c27321d9] Glob v1.3.1
  [86223c79] Graphs v1.13.1
  [34004b35] HypergeometricFunctions v0.3.28
  [615f187c] IfElse v0.1.1
  [3263718b] ImplicitDiscreteSolve v1.2.0
  [d25df0c9] Inflate v0.1.5
  [18e54dd8] IntegerMathUtils v0.1.3
  [8197267c] IntervalSets v0.7.11
  [3587e190] InverseFunctions v0.1.17
  [92d709cd] IrrationalConstants v0.2.6
  [82899510] IteratorInterfaceExtensions v1.0.0
  [692b3bcd] JLLWrappers v1.7.1
  [ae98c720] Jieko v0.2.1
  [98e50ef6] JuliaFormatter v2.1.6
⌅ [70703baa] JuliaSyntax v0.4.10
  [ccbc3e58] JumpProcesses v9.19.1
  [b964fa9f] LaTeXStrings v1.4.0
  [23fbe1c1] Latexify v0.16.10
  [10f19ff3] LayoutPointers v0.1.17
  [87fe0de2] LineSearch v0.1.4
  [d3d80556] LineSearches v7.4.0
  [2ab3a3ac] LogExpFunctions v0.3.29
  [d8e11817] MLStyle v0.4.17
  [1914dd2f] MacroTools v0.5.16
  [d125e4d3] ManualMemory v0.1.8
  [bb5d69b7] MaybeInplace v0.1.4
  [e1d29d7a] Missings v1.2.0
  [961ee093] ModelingToolkit v10.25.0
  [2e0e35c7] Moshi v0.3.7
  [46d2c3a1] MuladdMacro v0.2.4
  [102ac46a] MultivariatePolynomials v0.5.13
  [d8a4904e] MutableArithmetics v1.6.6
  [d41bc354] NLSolversBase v7.10.0
  [77ba4419] NaNMath v1.1.3
  [be0214bd] NonlinearSolveBase v2.0.0
  [6fe1bfb0] OffsetArrays v1.17.0
  [429524aa] Optim v1.13.2
  [bac558e1] OrderedCollections v1.8.1
  [bbf590c4] OrdinaryDiffEqCore v1.36.0
  [90014a1f] PDMats v0.11.35
  [d96e819e] Parameters v0.12.3
  [e409e4f3] PoissonRandom v0.4.7
  [f517fe37] Polyester v0.7.18
  [1d0040c9] PolyesterWeave v0.2.2
  [85a6dd25] PositiveFactorizations v0.2.4
  [d236fae5] PreallocationTools v0.4.34
  [aea7be01] PrecompileTools v1.3.3
  [21216c6a] Preferences v1.5.0
  [27ebfcd6] Primes v0.5.7
  [43287f4e] PtrArrays v1.3.0
  [1fd47b50] QuadGK v2.11.2
  [74087812] Random123 v1.7.1
  [e6cf234a] RandomNumbers v1.6.0
  [3cdcf5f2] RecipesBase v1.3.4
  [731186ca] RecursiveArrayTools v3.37.1
  [189a3867] Reexport v1.2.2
  [ae029012] Requires v1.3.1
  [ae5879a3] ResettableStacks v1.1.1
  [79098fc4] Rmath v0.8.0
  [7e49a35a] RuntimeGeneratedFunctions v0.5.15
  [9dfe8606] SCCNonlinearSolve v1.6.0
  [94e857df] SIMDTypes v0.1.0
  [0bca4576] SciMLBase v2.121.1
  [19f34311] SciMLJacobianOperators v0.1.11
  [c0aeaf25] SciMLOperators v1.9.0
  [431bcebd] SciMLPublic v1.0.0
  [53ae85a6] SciMLStructures v1.7.0
  [efcf1570] Setfield v1.1.2
  [727e6d20] SimpleNonlinearSolve v2.9.0
  [699a6c99] SimpleTraits v0.9.5
  [ce78b400] SimpleUnPack v1.1.0
  [a2af1166] SortingAlgorithms v1.2.2
  [276daf66] SpecialFunctions v2.6.1
  [aedffcd0] Static v1.3.0
  [0d7ed370] StaticArrayInterface v1.8.0
  [90137ffa] StaticArrays v1.9.15
  [1e83bf80] StaticArraysCore v1.4.3
  [10745b16] Statistics v1.11.1
  [82ae8749] StatsAPI v1.7.1
  [2913bbd2] StatsBase v0.34.6
  [4c63d2b9] StatsFuns v1.5.0
  [7792a7ef] StrideArraysCore v0.5.8
  [2efcf032] SymbolicIndexingInterface v0.3.45
⌃ [19f23fe9] SymbolicLimits v0.2.3
⌅ [d1185830] SymbolicUtils v3.32.0
  [0c5d862f] Symbolics v6.55.0
  [ed4db957] TaskLocalValues v0.1.3
  [8ea1fca8] TermInterface v2.0.0
  [1c621080] TestItems v1.0.0
  [8290d209] ThreadingUtilities v0.5.5
  [a759f4b9] TimerOutputs v0.5.29
  [410a4b4d] Tricks v0.1.12
  [781d530d] TruncatedStacktraces v1.4.0
  [5c2747f8] URIs v1.6.1
  [3a884ed6] UnPack v1.0.2
  [1986cc42] Unitful v1.25.0
  [a7c27f48] Unityper v0.1.6
  [61579ee1] Ghostscript_jll v9.55.1+0
  [aacddb02] JpegTurbo_jll v3.1.3+0
  [efe28fd5] OpenSpecFun_jll v0.5.6+0
  [f50d1b31] Rmath_jll v0.5.1+0
  [56f22d72] Artifacts v1.11.0
  [2a0f44e3] Base64 v1.11.0
  [ade2ca70] Dates v1.11.0
  [8ba89e20] Distributed v1.11.0
  [9fa8497b] Future v1.11.0
  [b77e0a4c] InteractiveUtils v1.11.0
  [ac6e5ff7] JuliaSyntaxHighlighting v1.12.0
  [8f399da3] Libdl v1.11.0
  [37e2e46d] LinearAlgebra v1.12.0
  [56ddb016] Logging v1.11.0
  [d6f4376e] Markdown v1.11.0
  [a63ad114] Mmap v1.11.0
  [de0858da] Printf v1.11.0
  [9a3f8284] Random v1.11.0
  [ea8e919c] SHA v0.7.0
  [9e88b42a] Serialization v1.11.0
  [1a1011a3] SharedArrays v1.11.0
  [6462fe0b] Sockets v1.11.0
  [2f01184e] SparseArrays v1.12.0
  [f489334b] StyledStrings v1.11.0
  [4607b0f0] SuiteSparse
  [fa267f1f] TOML v1.0.3
  [8dfed614] Test v1.11.0
  [cf7118a7] UUIDs v1.11.0
  [4ec0a83e] Unicode v1.11.0
  [e66e0078] CompilerSupportLibraries_jll v1.3.0+1
  [4536629a] OpenBLAS_jll v0.3.29+0
  [05823500] OpenLibm_jll v0.8.7+0
  [bea87d4a] SuiteSparse_jll v7.8.3+2
  [83775a58] Zlib_jll v1.3.1+2
  [8e850b90] libblastrampoline_jll v5.13.1+1
Info Packages marked with ⌃ and ⌅ have new versions available. Those with ⌃ may be upgradable, but those with ⌅ are restricted by compatibility constraints from upgrading. To see why use `status --outdated -m`

• Output of versioninfo()

Julia Version 1.12.0
Commit b907bd0600f (2025-10-07 15:42 UTC)
Build Info:
  Official https://julialang.org release
Platform Info:
  OS: Linux (x86_64-linux-gnu)
  CPU: 12 × AMD Ryzen 5 PRO 6650U with Radeon Graphics
  WORD_SIZE: 64
  LLVM: libLLVM-18.1.7 (ORCJIT, znver3)
  GC: Built with stock GC
Threads: 1 default, 1 interactive, 1 GC (on 12 virtual cores)

Additional context

Here is a comparison between the manifests of both ModelingToolkit versions as well in bold, aligned by package.

Related discussion:

• Update packages JuliaAstro/GeneralAstrodynamics.jl#268 (comment)
• Bounds Error in AttitudeFunction JuliaAstro/GeneralAstrodynamics.jl#270

Potentially related issue: #3848

[AayushSabharwal]

MTK needs more parameters than just the ones in your model. Use ModelingToolkit.get_p(sys, [p => [5, 6, 7]]) to generate the parameter vector and pass it to the ODEFunction.

[icweaver]

Hi Aayush, thanks for the tip! I think I got something working:

@independent_variables t
δ = Differential(t)

@variables (u(t))[1:2]
u = Symbolics.scalarize(u)

@parameters p[1:3]
p_scal = Symbolics.scalarize(p)

eqs = [
   δ(u[1]) ~ 0,
   δ(u[2]) ~ 0,
]

sys = complete(System(eqs, t, u, p_scal; name = :Test); split = false)

p_mtk = ModelingToolkit.get_p(sys, [p => [5, 6, 7]])

ODEF = ODEFunction{true, SciMLBase.FullSpecialize}(sys; jac = true)

ODEF([3.0, 4.0], p_mtk, NaN)

I see that the documentation for get_p warns that this is an internal function, so I was wondering if what I am trying to do is idiomatic. Thanks again for taking a look!