add downgrade workflow

.github/workflows/downgrade.yml

@@ -0,0 +1,77 @@
+name: Downgrade
+
+on:
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - 'LICENSE.md'
+      - 'README.md'
+      - '.zenodo.json'
+      - '.github/workflows/CompatHelper.yml'
+      - '.github/workflows/TagBot.yml'
+      - 'docs/**'
+  pull_request:
+    paths-ignore:
+      - 'LICENSE.md'
+      - 'README.md'
+      - '.zenodo.json'
+      - '.github/workflows/CompatHelper.yml'
+      - '.github/workflows/TagBot.yml'
+      - 'docs/**'
+  workflow_dispatch:
+
+concurrency:
+  # Skip intermediate builds: always.
+  # Cancel intermediate builds: only if it is a pull request build.
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
+
+# needed to allow julia-actions/cache to delete old caches that it has created
+permissions:
+  actions: write
+  contents: read
+
+jobs:
+  downgrade_test:
+    if: "!contains(github.event.head_commit.message, 'skip ci')"
+    name: Downgrade - ${{ matrix.trixi_test }} - ${{ matrix.os }} - ${{ matrix.arch }}
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        version:
+          - '1.10'
+        os:
+          - ubuntu-latest
+        arch:
+          - x64
+        trixi_test:
+          - upstream
+    steps:
+      - uses: actions/checkout@v6
+      - uses: julia-actions/setup-julia@v2
+        with:
+          version: ${{ matrix.version }}
+          arch: ${{ matrix.arch }}
+      - run: julia -e 'using InteractiveUtils; versioninfo(verbose=true)'
+      - uses: julia-actions/cache@v2
+      - uses: julia-actions/julia-downgrade-compat@v2
+        with:
+          skip: LinearAlgebra,Printf,Test
+          projects: ., test
+          mode: forcedeps
+      # We run the tests manually instead of using julia-action/julia-builpkg and julia-action/julia-runtest or `Pkg.test`
+      # because otherwise the downgraded Manifest.toml is not used in the tests under julia <v1.12
+      # see also https://github.com/julia-actions/julia-downgrade-compat/blob/00f940b7be2b50389571ed016d603be561649103/README.md#L89
+      - name: Run tests
+        run: |
+          julia --project=test --color=yes -e '
+            import Pkg
+            Pkg.develop(Pkg.PackageSpec(path=pwd()))
+            Pkg.instantiate()
+            Pkg.status(; mode = Pkg.PKGMODE_MANIFEST)
+            include("test/runtests.jl")
+          '
+        env:
+          TRIXI_TEST: ${{ matrix.trixi_test }}

Project.toml

@@ -17,7 +17,7 @@ LinearAlgebra = "1"
 MuladdMacro = "0.2.4"
 Printf = "1"
 Roots = "2.1.6"
-Static = "1.1.1"
-StaticArrays = "1.9"
+Static = "1.2"
+StaticArrays = "1.9.7"
 Trixi = "0.15"
 julia = "1.10"

test/Project.toml

@@ -17,5 +17,5 @@ Roots = "2.1.6"
 Symbolics = "7.14"
 Test = "1"
 Trixi = "0.15"
-TrixiBottomTopography = "0.1"
+TrixiBottomTopography = "0.1.1"
 TrixiTest = "0.2.1"