CI Health Check - Testing master branch

[ChrisRackauckas-Claude]

CI Health Check

This is an automated CI health check to verify the current state of the CI pipeline on the main branch.

Purpose

• Trigger CI to verify all tests and checks are passing
• Identify any issues with the main branch

Changes

• Added a blank line to README.md (trivial whitespace change)

This PR will be closed automatically after CI completes and results are analyzed.

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🤖 Generated by automated CI health check on Sun Dec 28 07:06:13 PM EST 2025

[ChrisRackauckas-Claude]

CI Health Check Results

Status: FAILURE ❌

Summary

The Tests (Core) workflow failed due to an incompatibility between MacroTools.jl and Julia 1.12.

Root Cause Analysis

The error occurs in MacroTools.jl's unresolve1 function at utils.jl:561:

LoadError: FieldError: type Base.MethodList has no field `mt`, available fields: `ms`, `tn`

The failing code in MacroTools is:

unresolve1(f::Function) = methods(f).mt.name

In Julia 1.12, the Base.MethodList struct has been changed - the mt field no longer exists and has been replaced with ms and tn fields. This is a breaking change in Julia's internal API that affects MacroTools.jl.

Stack Trace Location

• Error occurs in: FiniteStateProjection.jl/src/build_rhs.jl:107
• When calling: ex |> MacroTools.flatten |> MacroTools.prettify
• The prettify function internally uses unresolve which calls unresolve1

Affected Tests

• Telegraph test fails when loading due to this macro processing error

Next Steps

1. Upstream Issue: This needs to be fixed in MacroTools.jl - the unresolve1 function needs to be updated to handle the Julia 1.12 API change
2. Workaround: FiniteStateProjection.jl could potentially avoid calling prettify but this would affect code quality/readability

Recommendations

• File an issue in FluxML/MacroTools.jl about Julia 1.12 incompatibility
• Once MacroTools is fixed and released, FiniteStateProjection.jl's CI should pass

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🤖 Automated CI health check

[ChrisRackauckas-Claude]

Closing CI health check PR.

Result: CI is broken due to MacroTools.jl incompatibility with Julia 1.12.

An upstream issue has been filed: FluxML/MacroTools.jl#216

This is a dependency issue that needs to be fixed in MacroTools.jl before FiniteStateProjection.jl can pass CI on Julia 1.12.