From bfb82aa6a96b87b752ce89da65fe07741a5109a5 Mon Sep 17 00:00:00 2001
From: Claude <noreply@anthropic.com>
Date: Tue, 29 Jul 2025 13:17:51 -0400
Subject: [PATCH] Add downgrade CI workflow with Core test group
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This adds the standardized downgrade CI workflow following the SciMLBase.jl
template, configured to run the Core test group for lean testing
while verifying package compatibility with downgraded dependencies.

🤖 Generated with [Claude Code](https://claude.ai/code)

Co-Authored-By: Claude <noreply@anthropic.com>
---
 .github/workflows/Downgrade.yml | 34 +++++++++++++++++++++++++++++++++
 1 file changed, 34 insertions(+)
 create mode 100644 .github/workflows/Downgrade.yml

diff --git a/.github/workflows/Downgrade.yml b/.github/workflows/Downgrade.yml
new file mode 100644
index 000000000..70d072fe8
--- /dev/null
+++ b/.github/workflows/Downgrade.yml
@@ -0,0 +1,34 @@
+name: Downgrade
+on:
+  pull_request:
+    branches:
+      - master
+    paths-ignore:
+      - 'docs/**'
+  push:
+    branches:
+      - master
+    paths-ignore:
+      - 'docs/**'
+jobs:
+  test:
+    runs-on: ubuntu-latest
+    strategy:
+      matrix:
+        downgrade_mode: ['alldeps']
+        julia-version: ['1.10']
+        group: ['Core']
+    steps:
+      - uses: actions/checkout@v4
+      - uses: julia-actions/setup-julia@v2
+        with:
+          version: ${{ matrix.julia-version }}
+      - uses: julia-actions/julia-downgrade-compat@v2
+        with:
+          skip: Pkg,TOML
+      - uses: julia-actions/julia-buildpkg@v1
+      - uses: julia-actions/julia-runtest@v1
+        with:
+          ALLOW_RERESOLVE: false
+        env:
+          GROUP: ${{ matrix.group }}