[CI Broken] Multiple CI failures on master branch detected

[ChrisRackauckas-Claude]

CI Health Check Report - FAILURES DETECTED

Date: January 7, 2026
Branch: master
Commit: 1f267be (Merge pull request #662)
CI Run: https://github.com/SciML/StochasticDiffEq.jl/actions/runs/20739441512

@ChrisRackauckas - Multiple CI failures have been detected on the master branch as part of an automated CI health check.

Summary

Four distinct CI workflows are failing on master:

1. ❌ Downgrade - Dependency resolution failure
2. ❌ CI - Test failures in AlgConvergence3 group
3. ❌ format-check - Runic action missing Julia dependency
4. ❌ IntegrationTest - Downstream package test failures

---

1. Downgrade Test Failure

Status: ❌ FAILING
CI Run: https://github.com/SciML/StochasticDiffEq.jl/actions/runs/20739441523
Duration: ~12 minutes

Root Cause

Unsatisfiable dependency requirements detected between Symbolics, SciMLBase, DifferentiationInterface, and ModelingToolkit.

Error Message

ERROR: LoadError: Unsatisfiable requirements detected for package Symbolics [0c5d862f]:
 Symbolics [0c5d862f] log:
 ├─possible versions are: 0.1.0-7.4.1 or uninstalled
 ├─restricted by compatibility requirements with SciMLBase [0bca4576] to versions: 5.6.0-7.4.1
 │ └─SciMLBase [0bca4576] log:
 │   ├─possible versions are: 1.0.0-2.131.0
 │   ├─restricted to versions 2.125.0-2 by project, leaving only versions: 2.125.0-2.131.0
 │   └─restricted to versions 2.125.0 by an explicit requirement, leaving only versions: 2.125.0
 ├─restricted by compatibility requirements with DifferentiationInterface [a0c0ee7d] to versions: 5.27.1-6.58.0
 │ └─DifferentiationInterface [a0c0ee7d] log:
 │   ├─possible versions are: 0.1.0-0.7.13
 │   └─restricted to versions 0.7.4 by an explicit requirement, leaving only versions: 0.7.4
 └─restricted by compatibility requirements with ModelingToolkit [961ee093] to versions: 7.0.0-7.4.1 — no versions left
   └─ModelingToolkit [961ee093] log:
     ├─possible versions are: 0.0.1-11.5.0
     └─restricted to versions 11 by project, leaving only versions: 11.0.0-11.5.0

Analysis

The downgrade compatibility test is failing because:

• SciMLBase is pinned to 2.125.0
• DifferentiationInterface is pinned to 0.7.4
• ModelingToolkit requires version 11.x
• These constraints create incompatible requirements for Symbolics version

Suggested Fix

Review and update compatibility bounds in Project.toml for:

• Symbolics
• SciMLBase
• DifferentiationInterface
• ModelingToolkit

The dependency ecosystem may need coordinated version bumps across packages.

---

2. CI Test Failures (AlgConvergence3)

Status: ❌ FAILING
CI Run: https://github.com/SciML/StochasticDiffEq.jl/actions/runs/20739441512
Failed Jobs:

• test (AlgConvergence3, lts)
• test (AlgConvergence3, pre)
• test (AlgConvergence3, 1)

Error Message

Test Summary: | Pass  Fail  Total     Time
Split Tests   |    8     2     10  1m04.2s
ERROR: LoadError: Some tests did not pass: 8 passed, 2 failed, 0 errored, 0 broken.

Analysis

The AlgConvergence3 test group has 2 failing tests out of 10 total tests in the "Split Tests" suite. This appears to be a real test regression, not an infrastructure issue.

Suggested Fix

1. Run the AlgConvergence3 tests locally to reproduce
2. Identify which specific split tests are failing
3. Investigate if this is related to recent algorithm changes or numerical precision issues
4. Fix the underlying test failures

---

3. Format-Check Failure

Status: ❌ FAILING
CI Run: https://github.com/SciML/StochasticDiffEq.jl/actions/runs/20739441522
Duration: ~13 seconds

Root Cause

The Runic formatting action is missing Julia as a dependency.

Error Message

runic-action: julia is a required dependency but does not seem to be available.
Process completed with exit code 1.

Analysis

The fredrikekre/runic-action@v1 workflow step is running before Julia has been set up. This is a CI configuration issue.

Suggested Fix

The .github/workflows/format-check.yml workflow needs to be updated to include a Julia setup step before running Runic:

- name: Setup Julia
  uses: julia-actions/setup-julia@v2
  with:
    version: '1'
- name: Run Runic
  uses: fredrikekre/runic-action@v1

---

4. IntegrationTest Failures

Status: ❌ FAILING
CI Run: https://github.com/SciML/StochasticDiffEq.jl/actions/runs/20739441518
Failed Downstream Packages:

• StochasticDelayDiffEq.jl/All
• DiffEqNoiseProcess.jl/Core1

Analysis

Two downstream packages are failing their integration tests when using the current master branch of StochasticDiffEq.jl. This suggests that recent changes may have broken the downstream API or behavior.

Suggested Fix

1. Review recent commits for breaking changes
2. Check the full logs of the downstream test failures to identify specific API breakage
3. Either fix the breaking changes or coordinate version bumps with downstream packages

---

Priority Assessment

High Priority:

1. Downgrade - Blocks dependency resolution, affects all users trying to install
2. IntegrationTest - Breaks downstream packages, affects ecosystem

Medium Priority:
3. CI Tests (AlgConvergence3) - Real test failures indicate potential algorithm issues
4. format-check - Simple configuration fix, doesn't affect functionality

---

Recommended Action Plan

1. Fix the format-check workflow (quick win, ~5 minutes)
2. Investigate and resolve the dependency resolution issues (may require coordination with upstream packages)
3. Debug and fix the AlgConvergence3 test failures
4. Review downstream integration test failures and address breaking changes

---

Note: This issue was created by an automated CI health check system. All logs and error messages have been extracted from the CI runs linked above.