Exa getter

CHANGELOG.md

@@ -7,6 +7,27 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
+## [0.10.1] - 2026-04-22
+
+### 🚀 Enhancements
+
+#### Clarified :exa Backend Error Message
+
+- **Improved error message**: `get_build_examodel` now clearly explains that the Exa (:exa) modeler is unavailable for functional API (macro-free) models
+- **Actionable suggestions**: Error message now suggests using ADNLP (:adnlp) or the @def macro from CTParser.jl
+- **Better context**: Error reason explains the root cause (functional API does not generate Exa builder)
+- **Regression test**: Added `test_build_examodel.jl` to verify error message content
+
+### 🐛 Bug Fixes
+
+- Fixed misleading error message that incorrectly suggested "dynamics" instead of "Exa modeler"
+
+## [0.10.0] - 2026-04-20
+
+### 📦 Release
+
+- Initial stable release version (no breaking changes from 0.9.15-beta)
+
 ## [0.9.15-beta] - 2026-04-18
 
 ### 🚀 Enhancements

Project.toml

@@ -1,6 +1,6 @@
 name = "CTModels"
 uuid = "34c4fa32-2049-4079-8329-de33c2a22e2d"
-version = "0.10.0"
+version = "0.10.1"
 authors = ["Olivier Cots <olivier.cots@toulouse-inp.fr>"]
 
 [deps]

src/OCP/Building/model.jl

@@ -1391,7 +1391,7 @@ end
 """
 $(TYPEDSIGNATURES)
 
-Return an error (PreconditionError) since the model is not built with the :exa backend.
+Fallback method: throws a `PreconditionError` explaining that the `:exa` modeler is not available because the `Model` was assembled through the functional (macro-free) API and therefore carries no Exa builder.
 """
 function get_build_examodel(
     ::Model{
@@ -1409,10 +1409,10 @@ function get_build_examodel(
 )
     throw(
         Exceptions.PreconditionError(
-            "Cannot access dynamics";
-            reason="Model must be parsed with :exa backend first",
-            suggestion="Parse the OCP with backend=:exa before accessing dynamics",
-            context="dynamics accessor on unparsed model",
+            "The :exa modeler is not available for this model";
+            reason="this Model was built with the functional (macro-free) API (PreModel + time!/state!/control!/variable!/dynamics!/objective!/constraint! + build), which does not generate the Exa builder required by the Exa (:exa) modeler",
+            suggestion="either choose another modeler, e.g. ADNLP (:adnlp), or define the optimal control problem with the @def macro so that the Exa builder is generated",
+            context="get_build_examodel called on a Model built without an Exa builder",
         ),
     )
 end

test/suite/ocp/test_build_examodel.jl

@@ -0,0 +1,98 @@
+module TestBuildExamodel
+
+using Test: Test
+import CTBase.Exceptions
+using CTModels: CTModels
+
+const VERBOSE = isdefined(Main, :TestData) ? Main.TestData.VERBOSE : true
+const SHOWTIMING = isdefined(Main, :TestData) ? Main.TestData.SHOWTIMING : true
+
+function test_build_examodel()
+    Test.@testset "Build Examodel Tests" verbose=VERBOSE showtiming=SHOWTIMING begin
+
+        # ====================================================================
+        # UNIT TESTS - Error on functional API model
+        # ====================================================================
+
+        Test.@testset "get_build_examodel error on functional API model" begin
+            # Build a minimal OCP using the functional (macro-free) API
+            ocp = CTModels.PreModel()
+            CTModels.time!(ocp; t0=0.0, tf=1.0)
+            CTModels.state!(ocp, 2)
+            CTModels.control!(ocp, 1)
+
+            # Simple dynamics function
+            dynamics!(r, t, x, u, v) = (r[1] = x[2]; r[2] = u[1])
+            CTModels.dynamics!(ocp, dynamics!)
+
+            # Simple objective
+            CTModels.objective!(ocp, :min, mayer=(x0, xf) -> xf[1]^2)
+
+            # Set time dependence (required before build)
+            CTModels.time_dependence!(ocp, autonomous=true)
+
+            # Build without build_examodel (functional API)
+            model = CTModels.build(ocp)
+
+            # Attempting to get build_examodel should throw PreconditionError
+            Test.@test_throws Exceptions.PreconditionError CTModels.get_build_examodel(model)
+
+            # Verify the error message contains the key information
+            try
+                CTModels.get_build_examodel(model)
+                Test.@test false  # Should not reach here
+            catch err
+                Test.@test err isa Exceptions.PreconditionError
+                Test.@test occursin(":exa modeler", err.msg)
+                Test.@test occursin("functional", err.reason)
+                Test.@test occursin("macro-free", err.reason)
+                Test.@test occursin(":adnlp", err.suggestion)
+                Test.@test occursin("@def", err.suggestion)
+                Test.@test occursin("Exa builder", err.context)
+            end
+        end
+
+        # ====================================================================
+        # INTEGRATION TESTS - Verify functional API workflow
+        # ====================================================================
+
+        Test.@testset "Functional API workflow integration" begin
+            # Build a complete OCP using functional API
+            ocp = CTModels.PreModel()
+            CTModels.time!(ocp; t0=0.0, tf=1.0)
+            CTModels.state!(ocp, 2)
+            CTModels.control!(ocp, 1)
+            CTModels.dynamics!(ocp, (r, t, x, u, v) -> (r[1] = x[2]; r[2] = u[1]))
+            CTModels.objective!(ocp, :min, mayer=(x0, xf) -> xf[1]^2)
+
+            # Set time dependence (required before build)
+            CTModels.time_dependence!(ocp, autonomous=true)
+
+            # Build without build_examodel
+            model = CTModels.build(ocp)
+
+            # Verify model is built but has no Exa builder
+            Test.@test model isa CTModels.Model
+            Test.@test model.build_examodel === nothing
+
+            # Verify get_build_examodel throws informative error
+            try
+                CTModels.get_build_examodel(model)
+                Test.@test false  # Should not reach here
+            catch err
+                Test.@test err isa Exceptions.PreconditionError
+                Test.@test occursin(":exa modeler", err.msg)
+                Test.@test occursin("functional", err.reason)
+                Test.@test occursin("macro-free", err.reason)
+                Test.@test occursin(":adnlp", err.suggestion)
+                Test.@test occursin("@def", err.suggestion)
+                Test.@test occursin("Exa builder", err.context)
+            end
+        end
+    end
+end
+
+end # module
+
+# CRITICAL: Redefine in outer scope for TestRunner
+test_build_examodel() = TestBuildExamodel.test_build_examodel()