From d3b8ec9fc323dbea1a866d29377a9031481d0f8b Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 09:53:27 +0200
Subject: [PATCH 01/45] new CI test with system MPI and local t8code

---
 .github/workflows/ci.yml   | 169 +++++++++++++++++++++++++++++++++++++
 .github/workflows/test.yml |  74 ----------------
 2 files changed, 169 insertions(+), 74 deletions(-)
 create mode 100644 .github/workflows/ci.yml
 delete mode 100644 .github/workflows/test.yml

diff --git a/.github/workflows/ci.yml b/.github/workflows/ci.yml
new file mode 100644
index 0000000..9c37179
--- /dev/null
+++ b/.github/workflows/ci.yml
@@ -0,0 +1,169 @@
+name: Run tests
+
+on: 
+  push:
+    branches:
+      - main
+    paths-ignore:
+      - 'AUTHORS.md'
+      - 'CONTRIBUTING.md'
+      - 'LICENSE.md'
+      - 'NEWS.md'
+      - 'README.md'
+      - '.github/workflows/Downgrade.yml'
+      - '.github/workflows/FormatCheck.yml'
+      - '.github/workflows/SpellCheck.yml'
+      - '.github/workflows/TagBot.yml'
+      - '.github/dependabot.yml'
+      - '.gitignore'
+  pull_request:
+    paths-ignore:
+      - '.github/workflows/Downgrade.yml'
+      - '.github/workflows/FormatCheck.yml'
+      - '.github/workflows/SpellCheck.yml'
+      - '.github/workflows/TagBot.yml'
+      - '.github/dependabot.yml'
+      - '.gitignore'
+  workflow_dispatch:
+    inputs:
+      debug_enabled:
+        type: boolean
+        description: 'Run the build with tmate debugging enabled (https://github.com/marketplace/actions/debugging-with-tmate)'
+        required: false
+        default: false
+
+# Cancel redundant CI tests automatically
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: true
+
+jobs:
+  test:
+    if: "!contains(github.event.head_commit.message, 'skip ci')"
+    runs-on: ${{ matrix.os }}
+    strategy:
+      fail-fast: false
+      matrix:
+        julia-version: ['1.10', '1', 'nightly']
+        julia-arch: [x64, x86]
+        os: [ubuntu-latest, windows-latest]
+        mpi-provider: [JLL_MPI]
+        t8code_version: ['4.0.0']
+        t8code_snapshot: ['26.07']
+        include:
+        - julia-version: '1.10'
+          julia-arch: 'default'
+          os: macos-latest
+          mpi-provider: JLL_MPI
+          t8code_version: '4.0.0'
+          t8code_snapshot: '26.07
+        - julia-version: '1'
+          julia-arch: 'default'
+          os: macos-latest
+          mpi-provider: JLL_MPI
+          t8code_version: '4.0.0'
+          t8code_snapshot: '26.07
+        - julia-version: 'nightly'
+          julia-arch: 'default'
+          os: macos-latest
+          mpi-provider: JLL_MPI
+          t8code_version: '4.0.0'
+          t8code_snapshot: '26.07
+        - julia-version: '1.10'
+          julia-arch: 'default'
+          os: ubuntu-latest
+          mpi-provider: SYSTEM_MPI
+          t8code_version: '4.0.0'
+          t8code_snapshot: '26.07
+        - julia-version: '1'
+          julia-arch: 'default'
+          os: ubuntu-latest
+          mpi-provider: SYSTEM_MPI
+          t8code_version: '4.0.0'
+          t8code_snapshot: '26.07
+        - julia-version: 'nightly'
+          julia-arch: 'default'
+          os: ubuntu-latest
+          mpi-provider: SYSTEM_MPI
+          t8code_version: '4.0.0'
+          t8code_snapshot: '26.07
+    steps:
+      - name: Checkout repository
+        uses: actions/checkout@v7
+
+      - name: Enable Julia cache
+        uses: julia-actions/cache@v3
+
+      - name: Enable t8code cache
+        if: matrix.mpi-provider == 'SYSTEM_MPI'
+        id: cache-t8code
+        uses: actions/cache@v6
+        with:
+          path: ./t8code-local
+          key: ${{ matrix.os }}-${{ matrix.julia-arch }}-${{ matrix.t8code_version }}-${{ matrix.t8code_snapshot }}
+
+      - name: Install Julia
+        uses: julia-actions/setup-julia@v3
+        with:
+          version: ${{ matrix.julia-version }}
+          arch: ${{ matrix.julia-arch }}
+          show-versioninfo: true
+
+      - name: Install system MPI library
+        if: matrix.mpi-provider == 'SYSTEM_MPI'
+        run: |
+          sudo apt-get update
+          sudo apt-get install -y openmpi-bin libopenmpi-dev
+
+      - name: Install t8code
+        if: matrix.mpi-provider == 'SYSTEM_MPI' && steps.cache-t8code.outputs.cache-hit != 'true'
+        run: |
+          T8CODE_RELEASE=${{ matrix.t8code_version }}
+          mkdir t8code-local
+          cd t8code-local
+          wget https://github.com/DLR-AMR/t8code/releases/download/v${T8CODE_RELEASE}-${{ matrix.t8code_snapshot }}/T8CODE-${T8CODE_RELEASE}-Source.tar.gz
+          tar xf T8CODE-${T8CODE_RELEASE}-Source.tar.gz
+          mkdir build
+          cd build
+          cmake \
+              -DCMAKE_C_COMPILER=mpicc \
+              -DCMAKE_CXX_COMPILER=mpicxx \
+              -DCMAKE_BUILD_TYPE=Release \
+              -DCMAKE_INSTALL_PREFIX="$PWD/../prefix" \
+              -DT8CODE_BUILD_TESTS=OFF \
+              -DBUILD_GMOCK=OFF \
+              -DINSTALL_GTEST=OFF \
+              -DT8CODE_BUILD_TUTORIALS=OFF \
+              -DT8CODE_BUILD_EXAMPLES=OFF \
+              -DT8CODE_BUILD_BENCHMARKS=OFF \
+              -DT8CODE_ENABLE_MPI=ON \
+              -DT8CODE_BUILD_FORTRAN_INTERFACE=ON \
+              ../T8CODE-${T8CODE_RELEASE}-Source
+          make -j 2
+          make install
+
+      - name: Configure MPI.jl
+        if: matrix.mpi-provider == 'SYSTEM_MPI'
+        shell: julia --color=yes --project=test {0}
+        run: |
+          using Pkg
+          Pkg.instantiate()
+
+          # Use system MPI
+          using MPIPreferences
+          MPIPreferences.use_system_binary(; force = true)
+
+          # Use local t8code
+          using T8code
+          T8code.set_libraries_path!("../t8code-local/prefix/lib"; force = true)
+
+      - name: Run Julia build step
+        uses: julia-actions/julia-buildpkg@v1
+
+      - name: Run Julia tests
+        uses: julia-actions/julia-runtest@v1
+
+      # Enable tmate debugging of manually-triggered workflows if the input option was provided
+      - name: Setup tmate session
+        uses: mxschmitt/action-tmate@v3
+        if: github.event_name == 'workflow_dispatch' && inputs.debug_enabled
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
deleted file mode 100644
index 1d1ab8e..0000000
--- a/.github/workflows/test.yml
+++ /dev/null
@@ -1,74 +0,0 @@
-name: Run tests
-
-on: 
-  push:
-    branches:
-      - main
-    paths-ignore:
-      - 'AUTHORS.md'
-      - 'CITATION.bib'
-      - 'CONTRIBUTING.md'
-      - 'LICENSE.md'
-      - 'NEWS.md'
-      - 'README.md'
-      - '.github/workflows/CompatHelper.yml'
-      - '.github/workflows/TagBot.yml'
-      - '.gitignore'
-  pull_request:
-    paths-ignore:
-      - 'AUTHORS.md'
-      - 'CITATION.bib'
-      - 'CONTRIBUTING.md'
-      - 'LICENSE.md'
-      - 'NEWS.md'
-      - 'README.md'
-      - '.github/workflows/CompatHelper.yml'
-      - '.github/workflows/TagBot.yml'
-      - '.gitignore'
-  workflow_dispatch:
-    inputs:
-      debug_enabled:
-        type: boolean
-        description: 'Run the build with tmate debugging enabled (https://github.com/marketplace/actions/debugging-with-tmate)'
-        required: false
-        default: false
-
-# Cancel redundant CI tests automatically
-concurrency:
-  group: ${{ github.workflow }}-${{ github.ref }}
-  cancel-in-progress: true
-
-jobs:
-  test:
-    runs-on: ${{ matrix.os }}
-    strategy:
-      fail-fast: false
-      matrix:
-        julia-version: ['1.10', '1', 'nightly']
-        julia-arch: [x64, x86]
-        os: [ubuntu-latest, windows-latest]
-        include:
-        - julia-version: '1.10'
-          julia-arch: 'default'
-          os: macos-latest
-        - julia-version: '1'
-          julia-arch: 'default'
-          os: macos-latest
-        - julia-version: 'nightly'
-          julia-arch: 'default'
-          os: macos-latest
-    steps:
-      - uses: actions/checkout@v7
-      - uses: julia-actions/setup-julia@v3
-        with:
-          version: ${{ matrix.julia-version }}
-          arch: ${{ matrix.julia-arch }}
-      - uses: julia-actions/julia-buildpkg@v1
-      - uses: julia-actions/julia-runtest@v1
-        # with:
-        #   annotate: true
-        continue-on-error: false
-      # Enable tmate debugging of manually-triggered workflows if the input option was provided
-      - name: Setup tmate session
-        uses: mxschmitt/action-tmate@v3
-        if: ${{ github.event_name == 'workflow_dispatch' && inputs.debug_enabled }}

From 55fb452aeb90989ab1c19ee89baa72af9b47f5f1 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 09:53:51 +0200
Subject: [PATCH 02/45] add NEWS.md

---
 NEWS.md | 18 ++++++++++++++++++
 1 file changed, 18 insertions(+)
 create mode 100644 NEWS.md

diff --git a/NEWS.md b/NEWS.md
new file mode 100644
index 0000000..38b0ca0
--- /dev/null
+++ b/NEWS.md
@@ -0,0 +1,18 @@
+# Changelog
+
+T8code.jl follows the interpretation of
+[semantic versioning (semver)](https://julialang.github.io/Pkg.jl/dev/compatibility/#Version-specifier-format-1)
+used in the Julia ecosystem. Notable changes will be documented in this file
+for human readability.
+
+
+## Changes in the v0.9 lifecycle
+
+#### Added
+
+- Added `ExplicitImports` tests
+
+#### Changed
+
+- Updated to `Clang.jl` version 0.19
+- Based on t8code's July release 

From 4aa9f0a4681480f91270ae48a89d904ba489c77f Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 09:57:43 +0200
Subject: [PATCH 03/45] revert renaming

---
 .github/workflows/{ci.yml => test.yml} | 0
 1 file changed, 0 insertions(+), 0 deletions(-)
 rename .github/workflows/{ci.yml => test.yml} (100%)

diff --git a/.github/workflows/ci.yml b/.github/workflows/test.yml
similarity index 100%
rename from .github/workflows/ci.yml
rename to .github/workflows/test.yml

From a2bc9ef0680fdc9d27ef36aafb2924c6f27e476a Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:09:23 +0200
Subject: [PATCH 04/45] add julia compat bound to test

---
 test/Project.toml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/test/Project.toml b/test/Project.toml
index 8cdd8fe..28e6f8b 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -9,3 +9,4 @@ Aqua = "0.7, 0.8"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
 Test = "1"
+julia = "1.10"

From 4bc34d9cbf16ba0c482a90a7ef2b9b6ad21f7435 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:11:17 +0200
Subject: [PATCH 05/45] typo

using other list syntax now
---
 .github/workflows/test.yml | 34 ++++++++++++++++++++++------------
 1 file changed, 22 insertions(+), 12 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 9c37179..30bce21 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -44,49 +44,59 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
-        julia-version: ['1.10', '1', 'nightly']
-        julia-arch: [x64, x86]
-        os: [ubuntu-latest, windows-latest]
-        mpi-provider: [JLL_MPI]
-        t8code_version: ['4.0.0']
-        t8code_snapshot: ['26.07']
+        julia-version:
+          - '1.10'
+          - '1'
+          - 'nightly'
+        julia-arch:
+          - x64
+          - x86
+        os:
+          - ubuntu-latest
+          - windows-latest
+        mpi-provider:
+          - JLL_MPI
+        t8code_version:
+          - '4.0.0'
+        t8code_snapshot:
+          - '26.07'
         include:
         - julia-version: '1.10'
           julia-arch: 'default'
           os: macos-latest
           mpi-provider: JLL_MPI
           t8code_version: '4.0.0'
-          t8code_snapshot: '26.07
+          t8code_snapshot: '26.07'
         - julia-version: '1'
           julia-arch: 'default'
           os: macos-latest
           mpi-provider: JLL_MPI
           t8code_version: '4.0.0'
-          t8code_snapshot: '26.07
+          t8code_snapshot: '26.07'
         - julia-version: 'nightly'
           julia-arch: 'default'
           os: macos-latest
           mpi-provider: JLL_MPI
           t8code_version: '4.0.0'
-          t8code_snapshot: '26.07
+          t8code_snapshot: '26.07'
         - julia-version: '1.10'
           julia-arch: 'default'
           os: ubuntu-latest
           mpi-provider: SYSTEM_MPI
           t8code_version: '4.0.0'
-          t8code_snapshot: '26.07
+          t8code_snapshot: '26.07'
         - julia-version: '1'
           julia-arch: 'default'
           os: ubuntu-latest
           mpi-provider: SYSTEM_MPI
           t8code_version: '4.0.0'
-          t8code_snapshot: '26.07
+          t8code_snapshot: '26.07'
         - julia-version: 'nightly'
           julia-arch: 'default'
           os: ubuntu-latest
           mpi-provider: SYSTEM_MPI
           t8code_version: '4.0.0'
-          t8code_snapshot: '26.07
+          t8code_snapshot: '26.07'
     steps:
       - name: Checkout repository
         uses: actions/checkout@v7

From 90fb0dca4bd8b8ce5483e66c438b4c5f44e1e06c Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:18:53 +0200
Subject: [PATCH 06/45] try to dev T8code

---
 .github/workflows/test.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 30bce21..da8f65e 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -164,6 +164,7 @@ jobs:
           MPIPreferences.use_system_binary(; force = true)
 
           # Use local t8code
+          Pkg.develop(path="..")
           using T8code
           T8code.set_libraries_path!("../t8code-local/prefix/lib"; force = true)
 

From fb22326a80638f6c6792f26976dc82eec3a5df2c Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:27:06 +0200
Subject: [PATCH 07/45] relative to project

---
 .github/workflows/test.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index da8f65e..0773a58 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -164,7 +164,7 @@ jobs:
           MPIPreferences.use_system_binary(; force = true)
 
           # Use local t8code
-          Pkg.develop(path="..")
+          Pkg.develop(path=joinpath(Base.active_project(), ".."))
           using T8code
           T8code.set_libraries_path!("../t8code-local/prefix/lib"; force = true)
 

From e3dbb10ac29245520d1597dafa08fe3a349947df Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:35:58 +0200
Subject: [PATCH 08/45] explicit arch

---
 .github/workflows/test.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 0773a58..4418004 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -80,19 +80,19 @@ jobs:
           t8code_version: '4.0.0'
           t8code_snapshot: '26.07'
         - julia-version: '1.10'
-          julia-arch: 'default'
+          julia-arch: 'x64'
           os: ubuntu-latest
           mpi-provider: SYSTEM_MPI
           t8code_version: '4.0.0'
           t8code_snapshot: '26.07'
         - julia-version: '1'
-          julia-arch: 'default'
+          julia-arch: 'x64'
           os: ubuntu-latest
           mpi-provider: SYSTEM_MPI
           t8code_version: '4.0.0'
           t8code_snapshot: '26.07'
         - julia-version: 'nightly'
-          julia-arch: 'default'
+          julia-arch: 'x64'
           os: ubuntu-latest
           mpi-provider: SYSTEM_MPI
           t8code_version: '4.0.0'

From e64707d38227233625cd89c99092d9e5490b14b8 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:36:19 +0200
Subject: [PATCH 09/45] use dirname

---
 .github/workflows/test.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 4418004..d24c0fc 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -164,7 +164,7 @@ jobs:
           MPIPreferences.use_system_binary(; force = true)
 
           # Use local t8code
-          Pkg.develop(path=joinpath(Base.active_project(), ".."))
+          Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
           using T8code
           T8code.set_libraries_path!("../t8code-local/prefix/lib"; force = true)
 

From d24cb7c2e9841f5674ffc0b4734101506cb9fbf7 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:36:39 +0200
Subject: [PATCH 10/45] wrong path?

---
 .github/workflows/test.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d24c0fc..1ba58df 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -166,7 +166,7 @@ jobs:
           # Use local t8code
           Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
           using T8code
-          T8code.set_libraries_path!("../t8code-local/prefix/lib"; force = true)
+          T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)
 
       - name: Run Julia build step
         uses: julia-actions/julia-buildpkg@v1

From 48228d926127bbd0cad06321112707e4d2049303 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:43:34 +0200
Subject: [PATCH 11/45] dev first?

---
 .github/workflows/test.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 1ba58df..bf2e368 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -157,6 +157,7 @@ jobs:
         shell: julia --color=yes --project=test {0}
         run: |
           using Pkg
+          Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
           Pkg.instantiate()
 
           # Use system MPI
@@ -164,7 +165,6 @@ jobs:
           MPIPreferences.use_system_binary(; force = true)
 
           # Use local t8code
-          Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
           using T8code
           T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)
 

From bdb6c6ded82e02e34f2bc2ec846053b2b51d066a Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:50:18 +0200
Subject: [PATCH 12/45] sequence

---
 .github/workflows/test.yml | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bf2e368..3cbb565 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -160,12 +160,13 @@ jobs:
           Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
           Pkg.instantiate()
 
-          # Use system MPI
           using MPIPreferences
+          using T8code
+
+          # Use system MPI
           MPIPreferences.use_system_binary(; force = true)
 
           # Use local t8code
-          using T8code
           T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)
 
       - name: Run Julia build step

From 8c5739006467e130a435e057d83a353bc791ccc5 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 10:59:29 +0200
Subject: [PATCH 13/45] split configure steps

---
 .github/workflows/test.yml | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 3cbb565..bad19a1 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -157,16 +157,21 @@ jobs:
         shell: julia --color=yes --project=test {0}
         run: |
           using Pkg
-          Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
           Pkg.instantiate()
 
-          using MPIPreferences
-          using T8code
-
           # Use system MPI
+          using MPIPreferences
           MPIPreferences.use_system_binary(; force = true)
 
+      - name: Configure T8code.jl
+        if: matrix.mpi-provider == 'SYSTEM_MPI'
+        shell: julia --color=yes --project=test {0}
+        run: |
+          using Pkg
+          Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
+
           # Use local t8code
+          using T8code
           T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)
 
       - name: Run Julia build step

From b641fd9a29cd07a872c9652c1f5edefefa7a37a1 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 11:11:42 +0200
Subject: [PATCH 14/45] OpenMPI 4 workaround

---
 .github/workflows/test.yml | 9 +++++++++
 1 file changed, 9 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bad19a1..bc97a4a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -101,6 +101,11 @@ jobs:
       - name: Checkout repository
         uses: actions/checkout@v7
 
+      - name: Set environment variables
+        shell: bash
+        run: |
+          echo "JULIA_MPI_PROVIDER=${{ matrix.mpi-provider }}" >> $GITHUB_ENV
+
       - name: Enable Julia cache
         uses: julia-actions/cache@v3
 
@@ -170,6 +175,10 @@ jobs:
           using Pkg
           Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
 
+          # Workaround
+          # https://github.com/trixi-framework/libtrixi/issues/237
+          Pkg.add(name="OpenMPI_jll", version="4")
+
           # Use local t8code
           using T8code
           T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)

From a20a02708075d9af6b83c49bc80aac558f8b3a8b Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 11:29:47 +0200
Subject: [PATCH 15/45] workaround needed in tests as well

---
 .github/workflows/test.yml | 4 ----
 test/Project.toml          | 2 ++
 2 files changed, 2 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index bc97a4a..fdb0df8 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -175,10 +175,6 @@ jobs:
           using Pkg
           Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
 
-          # Workaround
-          # https://github.com/trixi-framework/libtrixi/issues/237
-          Pkg.add(name="OpenMPI_jll", version="4")
-
           # Use local t8code
           using T8code
           T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)
diff --git a/test/Project.toml b/test/Project.toml
index 28e6f8b..2646619 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -2,11 +2,13 @@
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"
 MPIPreferences = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
+OpenMPI_jll = "fe0851c0-eecd-5654-98d4-656369965a5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Aqua = "0.7, 0.8"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
+OpenMPI_jll = "4"
 Test = "1"
 julia = "1.10"

From 2b9464da6764735af25ca993fe392c43c8f08762 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 11:45:31 +0200
Subject: [PATCH 16/45] add MPI testing file

---
 test/test_all.jl  |  7 +++++++
 test/test_init.jl |  4 ----
 test/test_mpi.jl  | 12 ++++++++++++
 3 files changed, 19 insertions(+), 4 deletions(-)
 create mode 100644 test/test_mpi.jl

diff --git a/test/test_all.jl b/test/test_all.jl
index cfc21da..787120d 100644
--- a/test/test_all.jl
+++ b/test/test_all.jl
@@ -17,6 +17,13 @@ comm = MPI.COMM_WORLD
 CI_ON_WINDOWS = (get(ENV, "GITHUB_ACTIONS", false) == "true") && Sys.iswindows()
 CI_ON_MACOS = (get(ENV, "GITHUB_ACTIONS", false) == "true") && Sys.isapple()
 
+# When run in CI, check if we are running with system MPI or Julia artifacts
+JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
+
+@testset "MPI" begin
+    include("test_mpi.jl")
+end
+
 @testset "init" begin
     include("test_init.jl")
 end
diff --git a/test/test_init.jl b/test/test_init.jl
index 88d9e6b..a22a539 100644
--- a/test/test_init.jl
+++ b/test/test_init.jl
@@ -1,7 +1,3 @@
-@testset "T8code.uses_mpi" begin
-    @test T8code.uses_mpi() == true
-end
-
 @testset "T8code.init" begin
     @test_nowarn T8code.Libt8.sc_init(comm, 0, 1, C_NULL, SC_LP_DEFAULT)
     @test_nowarn t8_init(SC_LP_DEFAULT)
diff --git a/test/test_mpi.jl b/test/test_mpi.jl
new file mode 100644
index 0000000..1d40027
--- /dev/null
+++ b/test/test_mpi.jl
@@ -0,0 +1,12 @@
+@testset "Conditional loading of t8code_jll"
+    # TODO adapt once implemented
+    if JULIA_MPI_PROVIDER == "SYSTEM_MPI"
+        @test :t8code_jll in names(Main; imported=true)
+    else
+        @test :t8code_jll in names(Main; imported=true)
+    end
+end
+
+@testset "T8code.uses_mpi" begin
+    @test T8code.uses_mpi() == true
+end

From c4adcf86a96f790787f14e55f6fca3345f4bafa2 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 15 Sep 2026 23:18:49 +0200
Subject: [PATCH 17/45] only load t8code_jll if preferences say so

---
 src/Libt8.jl | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/Libt8.jl b/src/Libt8.jl
index 2c9c822..f6ed22f 100644
--- a/src/Libt8.jl
+++ b/src/Libt8.jl
@@ -7,10 +7,12 @@ to_c_type_pairs(va_list) = map(enumerate(to_c_type.(va_list))) do (ind, type)
     :(va_list[$ind]::$type)
 end
 
-using t8code_jll: t8code_jll
-export t8code_jll
-
 using ..T8code: _PREFERENCE_LIBT8, _PREFERENCE_LIBP4EST, _PREFERENCE_LIBSC
+
+@static if _PREFERENCE_LIBT8 == "t8code_jll" || _PREFERENCE_LIBP4EST == "t8code_jll" || _PREFERENCE_LIBSC == "t8code_jll"
+    using t8code_jll: t8code_jll
+end
+
 using MPIPreferences: MPIPreferences
 
 @static if _PREFERENCE_LIBT8 == "t8code_jll" && MPIPreferences.binary == "system"

From a7efdb8f3fc756213812473644be0fac19077097 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 11:49:00 +0200
Subject: [PATCH 18/45] remove workaround

---
 test/Project.toml | 2 --
 test/test_mpi.jl  | 9 ++-------
 2 files changed, 2 insertions(+), 9 deletions(-)

diff --git a/test/Project.toml b/test/Project.toml
index 2646619..28e6f8b 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -2,13 +2,11 @@
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"
 MPIPreferences = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
-OpenMPI_jll = "fe0851c0-eecd-5654-98d4-656369965a5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Aqua = "0.7, 0.8"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
-OpenMPI_jll = "4"
 Test = "1"
 julia = "1.10"
diff --git a/test/test_mpi.jl b/test/test_mpi.jl
index 1d40027..9fb80af 100644
--- a/test/test_mpi.jl
+++ b/test/test_mpi.jl
@@ -1,10 +1,5 @@
-@testset "Conditional loading of t8code_jll"
-    # TODO adapt once implemented
-    if JULIA_MPI_PROVIDER == "SYSTEM_MPI"
-        @test :t8code_jll in names(Main; imported=true)
-    else
-        @test :t8code_jll in names(Main; imported=true)
-    end
+@testset "Conditional loading of t8code_jll" begin
+    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") && !(:t8code_jll in names(Main; imported=true))
 end
 
 @testset "T8code.uses_mpi" begin

From f87e42d61ed66d305f8c735bbcc6d54b23e050e1 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 11:52:35 +0200
Subject: [PATCH 19/45] fix

---
 test/test_mpi.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/test_mpi.jl b/test/test_mpi.jl
index 9fb80af..3865ea7 100644
--- a/test/test_mpi.jl
+++ b/test/test_mpi.jl
@@ -1,5 +1,5 @@
 @testset "Conditional loading of t8code_jll" begin
-    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") && !(:t8code_jll in names(Main; imported=true))
+    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") != (:t8code_jll in names(Main; imported=true))
 end
 
 @testset "T8code.uses_mpi" begin

From 0da9a67c9571526d198f9db85cd8f1aa6a9f6128 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 11:55:44 +0200
Subject: [PATCH 20/45] OpenMPI_jll v4 again

---
 test/Project.toml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/test/Project.toml b/test/Project.toml
index 28e6f8b..2646619 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -2,11 +2,13 @@
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"
 MPIPreferences = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
+OpenMPI_jll = "fe0851c0-eecd-5654-98d4-656369965a5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Aqua = "0.7, 0.8"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
+OpenMPI_jll = "4"
 Test = "1"
 julia = "1.10"

From e968a65ccf19d0ccb35c23c578df21a58ae2f63a Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 12:09:09 +0200
Subject: [PATCH 21/45] check module T8code

---
 test/test_mpi.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/test_mpi.jl b/test/test_mpi.jl
index 3865ea7..ae3eb09 100644
--- a/test/test_mpi.jl
+++ b/test/test_mpi.jl
@@ -1,5 +1,5 @@
 @testset "Conditional loading of t8code_jll" begin
-    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") != (:t8code_jll in names(Main; imported=true))
+    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") != (:t8code_jll in names(T8code; imported=true))
 end
 
 @testset "T8code.uses_mpi" begin

From 18949e73325e4f71d44cb32706fc4b644c274a74 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 12:09:22 +0200
Subject: [PATCH 22/45] skip aqua test when running with system MPI

---
 test/test_aqua.jl | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index 221a746..9212a09 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -4,8 +4,14 @@ using Aqua
 using Test
 using T8code
 
-@testset "Aqua.jl" begin
-    Aqua.test_all(T8code)
+# When run in CI, check if we are running with system MPI or Julia artifacts
+JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
+
+# in case we are running with system MPI t8code_jll will not be loaded
+if JULIA_MPI_PROVIDER == "JLL_MPI"
+    @testset "Aqua.jl" begin
+        Aqua.test_all(T8code)
+    end
 end
 
 end #module

From 8d06b57a5dc5c20e508446f02879c45655b387f9 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 12:32:15 +0200
Subject: [PATCH 23/45] based on loaded_modules

---
 test/test_mpi.jl | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/test/test_mpi.jl b/test/test_mpi.jl
index ae3eb09..3390d66 100644
--- a/test/test_mpi.jl
+++ b/test/test_mpi.jl
@@ -1,5 +1,6 @@
 @testset "Conditional loading of t8code_jll" begin
-    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") != (:t8code_jll in names(T8code; imported=true))
+    t8code_jll_loaded = any(m -> nameof(m) === :t8code_jll, values(Base.loaded_modules))
+    @test (JULIA_MPI_PROVIDER == "SYSTEM_MPI") != t8code_jll_loaded
 end
 
 @testset "T8code.uses_mpi" begin

From 35403bc5513b25f25abf0f7628cd6f0b1514cd77 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 12:52:44 +0200
Subject: [PATCH 24/45] lower bound reported by Downgrade

---
 test/Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/Project.toml b/test/Project.toml
index 2646619..58d13b5 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -9,6 +9,6 @@ Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 Aqua = "0.7, 0.8"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
-OpenMPI_jll = "4"
+OpenMPI_jll = "4.1.9"
 Test = "1"
 julia = "1.10"

From d495f659ba41d532720a15c83bccc45607210a45 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 12:53:04 +0200
Subject: [PATCH 25/45] need absolute path

---
 .github/workflows/test.yml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index fdb0df8..7179b2a 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -177,7 +177,7 @@ jobs:
 
           # Use local t8code
           using T8code
-          T8code.set_libraries_path!("./t8code-local/prefix/lib"; force = true)
+          T8code.set_libraries_path!(abspath("./t8code-local/prefix/lib"); force = true)
 
       - name: Run Julia build step
         uses: julia-actions/julia-buildpkg@v1

From 630642151fea1854dabffdeba48a8bf63b28549d Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 13:05:57 +0200
Subject: [PATCH 26/45] check again

---
 .github/workflows/test.yml | 5 +++++
 test/Project.toml          | 2 --
 2 files changed, 5 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 7179b2a..152cb36 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -173,6 +173,11 @@ jobs:
         shell: julia --color=yes --project=test {0}
         run: |
           using Pkg
+
+          # Workaround
+          # https://github.com/trixi-framework/libtrixi/issues/237
+          Pkg.add(name="OpenMPI_jll", version="4")
+
           Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
 
           # Use local t8code
diff --git a/test/Project.toml b/test/Project.toml
index 58d13b5..28e6f8b 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -2,13 +2,11 @@
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 MPI = "da04e1cc-30fd-572f-bb4f-1f8673147195"
 MPIPreferences = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
-OpenMPI_jll = "fe0851c0-eecd-5654-98d4-656369965a5c"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
 Aqua = "0.7, 0.8"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
-OpenMPI_jll = "4.1.9"
 Test = "1"
 julia = "1.10"

From f4b4b60aea65f7efdee9be0b3512c58b66c1ef62 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 15:45:38 +0200
Subject: [PATCH 27/45] Revert "only load t8code_jll if preferences say so"

This reverts commit c4adcf86a96f790787f14e55f6fca3345f4bafa2.
---
 src/Libt8.jl | 8 +++-----
 1 file changed, 3 insertions(+), 5 deletions(-)

diff --git a/src/Libt8.jl b/src/Libt8.jl
index f6ed22f..2c9c822 100644
--- a/src/Libt8.jl
+++ b/src/Libt8.jl
@@ -7,12 +7,10 @@ to_c_type_pairs(va_list) = map(enumerate(to_c_type.(va_list))) do (ind, type)
     :(va_list[$ind]::$type)
 end
 
-using ..T8code: _PREFERENCE_LIBT8, _PREFERENCE_LIBP4EST, _PREFERENCE_LIBSC
-
-@static if _PREFERENCE_LIBT8 == "t8code_jll" || _PREFERENCE_LIBP4EST == "t8code_jll" || _PREFERENCE_LIBSC == "t8code_jll"
-    using t8code_jll: t8code_jll
-end
+using t8code_jll: t8code_jll
+export t8code_jll
 
+using ..T8code: _PREFERENCE_LIBT8, _PREFERENCE_LIBP4EST, _PREFERENCE_LIBSC
 using MPIPreferences: MPIPreferences
 
 @static if _PREFERENCE_LIBT8 == "t8code_jll" && MPIPreferences.binary == "system"

From 0e4a4cd65f4dc631db749258ea8336133675a372 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 22 Sep 2026 16:28:49 +0200
Subject: [PATCH 28/45] free T8code package again afterwards

---
 .github/workflows/test.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 152cb36..6b20e3d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -178,11 +178,11 @@ jobs:
           # https://github.com/trixi-framework/libtrixi/issues/237
           Pkg.add(name="OpenMPI_jll", version="4")
 
+          # Use local t8code, just to set the preferences
           Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
-
-          # Use local t8code
           using T8code
           T8code.set_libraries_path!(abspath("./t8code-local/prefix/lib"); force = true)
+          Pkg.free("T8code")
 
       - name: Run Julia build step
         uses: julia-actions/julia-buildpkg@v1

From 79ef50a12e098f276cbb962f28cdf483164ae8e6 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Tue, 15 Sep 2026 23:18:49 +0200
Subject: [PATCH 29/45] only load t8code_jll if preferences say so

---
 src/Libt8.jl | 8 +++++---
 1 file changed, 5 insertions(+), 3 deletions(-)

diff --git a/src/Libt8.jl b/src/Libt8.jl
index 2c9c822..f6ed22f 100644
--- a/src/Libt8.jl
+++ b/src/Libt8.jl
@@ -7,10 +7,12 @@ to_c_type_pairs(va_list) = map(enumerate(to_c_type.(va_list))) do (ind, type)
     :(va_list[$ind]::$type)
 end
 
-using t8code_jll: t8code_jll
-export t8code_jll
-
 using ..T8code: _PREFERENCE_LIBT8, _PREFERENCE_LIBP4EST, _PREFERENCE_LIBSC
+
+@static if _PREFERENCE_LIBT8 == "t8code_jll" || _PREFERENCE_LIBP4EST == "t8code_jll" || _PREFERENCE_LIBSC == "t8code_jll"
+    using t8code_jll: t8code_jll
+end
+
 using MPIPreferences: MPIPreferences
 
 @static if _PREFERENCE_LIBT8 == "t8code_jll" && MPIPreferences.binary == "system"

From 9b8b75bad4717d4635306da95210b5123978941a Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 14:23:48 +0200
Subject: [PATCH 30/45] remove build step

---
 .github/workflows/test.yml | 3 ---
 1 file changed, 3 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 6b20e3d..d5943a3 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -184,9 +184,6 @@ jobs:
           T8code.set_libraries_path!(abspath("./t8code-local/prefix/lib"); force = true)
           Pkg.free("T8code")
 
-      - name: Run Julia build step
-        uses: julia-actions/julia-buildpkg@v1
-
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1
 

From 4fda35a882db080adcb52fffcef0f3da8a5d2ba7 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 14:24:20 +0200
Subject: [PATCH 31/45] conditional ignore for Aqua test

---
 test/test_aqua.jl | 13 ++++++++-----
 1 file changed, 8 insertions(+), 5 deletions(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index 9212a09..f9704cb 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -7,11 +7,14 @@ using T8code
 # When run in CI, check if we are running with system MPI or Julia artifacts
 JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
 
-# in case we are running with system MPI t8code_jll will not be loaded
-if JULIA_MPI_PROVIDER == "JLL_MPI"
-    @testset "Aqua.jl" begin
-        Aqua.test_all(T8code)
+@testset "Aqua.jl" begin
+    # in case we are running with system MPI t8code_jll will not be loaded
+    if JULIA_MPI_PROVIDER == "SYSTEM_MPI"
+        stale_deps_ignore = [:T8code]
+    else
+        stale_deps_ignore = []
     end
-end
 
+    Aqua.test_all(T8code; stale_deps=(ignore=stale_deps_ignore,))
+end
 end #module

From 510aeb9a19531f34abb45c1a7b7ff6a603e883f3 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 14:27:52 +0200
Subject: [PATCH 32/45] fmt

---
 test/test_aqua.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index 6ad00db..b23809b 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -16,7 +16,7 @@ JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
         stale_deps_ignore = []
     end
 
-    Aqua.test_all(T8code; stale_deps=(ignore=stale_deps_ignore,))
+    Aqua.test_all(T8code; stale_deps = (ignore = stale_deps_ignore,))
 end
 
 @testset "ExplicitImports.jl" begin

From c4b139ce4a377727f02f991ad2de61346ec1f201 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 14:34:05 +0200
Subject: [PATCH 33/45] pass Tuple to stale_deps

---
 test/test_aqua.jl | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index b23809b..c32d482 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -11,12 +11,12 @@ JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
 @testset "Aqua.jl" begin
     # in case we are running with system MPI t8code_jll will not be loaded
     if JULIA_MPI_PROVIDER == "SYSTEM_MPI"
-        stale_deps_ignore = [:T8code]
+        stale_deps_ignore = (ignore = [:T8code],)
     else
-        stale_deps_ignore = []
+        stale_deps_ignore = ()
     end
 
-    Aqua.test_all(T8code; stale_deps = (ignore = stale_deps_ignore,))
+    Aqua.test_all(T8code; stale_deps = stale_deps_ignore)
 end
 
 @testset "ExplicitImports.jl" begin

From 73d87263440cf48ab45dc8298b9c36ade3e2a51f Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 14:42:05 +0200
Subject: [PATCH 34/45] correct ignore

---
 test/test_aqua.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index c32d482..a201f7c 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -11,7 +11,7 @@ JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
 @testset "Aqua.jl" begin
     # in case we are running with system MPI t8code_jll will not be loaded
     if JULIA_MPI_PROVIDER == "SYSTEM_MPI"
-        stale_deps_ignore = (ignore = [:T8code],)
+        stale_deps_ignore = (ignore = [:t8code_jll],)
     else
         stale_deps_ignore = ()
     end

From 3057762ff43ff908c79ef92159bf46042f6a5a3a Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 15:12:34 +0200
Subject: [PATCH 35/45] conditionally disable persistant tasks check

---
 test/test_aqua.jl | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index a201f7c..a3269af 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -12,11 +12,15 @@ JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
     # in case we are running with system MPI t8code_jll will not be loaded
     if JULIA_MPI_PROVIDER == "SYSTEM_MPI"
         stale_deps_ignore = (ignore = [:t8code_jll],)
+        test_persistent_tasks = false
     else
         stale_deps_ignore = ()
+        test_persistent_tasks = true
     end
 
-    Aqua.test_all(T8code; stale_deps = stale_deps_ignore)
+    Aqua.test_all(T8code;
+                  test_persistent_tasks = test_persistent_tasks,
+                  stale_deps = stale_deps_ignore)
 end
 
 @testset "ExplicitImports.jl" begin

From 2e62599deaf0ee6710959265c56f5a032d9fd4c2 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 15:31:29 +0200
Subject: [PATCH 36/45] can we always use Aqua 0.8?

---
 test/Project.toml | 2 +-
 test/test_aqua.jl | 2 +-
 2 files changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/Project.toml b/test/Project.toml
index 7701746..d72741d 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -6,7 +6,7 @@ MPIPreferences = "3da0fdf6-3ccc-4f1b-acd9-58baa6c99267"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
-Aqua = "0.7, 0.8"
+Aqua = "0.8"
 ExplicitImports = "1.15"
 MPI = "0.20.6"
 MPIPreferences = "0.1.6"
diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index a3269af..48a5d04 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -19,7 +19,7 @@ JULIA_MPI_PROVIDER = get(ENV, "JULIA_MPI_PROVIDER", "JLL_MPI")
     end
 
     Aqua.test_all(T8code;
-                  test_persistent_tasks = test_persistent_tasks,
+                  persistent_tasks = test_persistent_tasks,
                   stale_deps = stale_deps_ignore)
 end
 

From 6b5d36debb007be0944309b68d4827e9ea221e60 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 16:10:42 +0200
Subject: [PATCH 37/45] do not use T8code to set the preferences

---
 .github/workflows/test.yml | 21 ++++++++++-----------
 1 file changed, 10 insertions(+), 11 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index d5943a3..78cd2fd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -172,17 +172,16 @@ jobs:
         if: matrix.mpi-provider == 'SYSTEM_MPI'
         shell: julia --color=yes --project=test {0}
         run: |
-          using Pkg
-
-          # Workaround
-          # https://github.com/trixi-framework/libtrixi/issues/237
-          Pkg.add(name="OpenMPI_jll", version="4")
-
-          # Use local t8code, just to set the preferences
-          Pkg.develop(path=joinpath(dirname(Base.active_project()), ".."))
-          using T8code
-          T8code.set_libraries_path!(abspath("./t8code-local/prefix/lib"); force = true)
-          Pkg.free("T8code")
+          using Preferences, UUIDs
+          set_preferences!(
+           UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
+           "libt8" => "./t8code-local/prefix/lib/libt8.so", force = true)
+          set_preferences!(
+           UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
+           "libp4est" => "./t8code-local/prefix/lib/libp4est.so", force = true)
+          set_preferences!(
+           UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
+           "libsc" => "./t8code-local/prefix/lib/libsc.so", force = true)
 
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1

From b257542055a60268640c573547fdc88e8f2ce7fd Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 16:11:44 +0200
Subject: [PATCH 38/45] use root project

---
 .github/workflows/test.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 78cd2fd..650853d 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -159,7 +159,7 @@ jobs:
 
       - name: Configure MPI.jl
         if: matrix.mpi-provider == 'SYSTEM_MPI'
-        shell: julia --color=yes --project=test {0}
+        shell: julia --color=yes --project=. {0}
         run: |
           using Pkg
           Pkg.instantiate()
@@ -170,7 +170,7 @@ jobs:
 
       - name: Configure T8code.jl
         if: matrix.mpi-provider == 'SYSTEM_MPI'
-        shell: julia --color=yes --project=test {0}
+        shell: julia --color=yes --project=. {0}
         run: |
           using Preferences, UUIDs
           set_preferences!(

From 487483164e712223bff930f44f12b20f258df35b Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 16:22:41 +0200
Subject: [PATCH 39/45] abspath

---
 .github/workflows/test.yml | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 650853d..11a827f 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -175,13 +175,13 @@ jobs:
           using Preferences, UUIDs
           set_preferences!(
            UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
-           "libt8" => "./t8code-local/prefix/lib/libt8.so", force = true)
+           "libt8" => abspath("./t8code-local/prefix/lib/libt8.so"), force = true)
           set_preferences!(
            UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
-           "libp4est" => "./t8code-local/prefix/lib/libp4est.so", force = true)
+           "libp4est" => abspath("./t8code-local/prefix/lib/libp4est.so"), force = true)
           set_preferences!(
            UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
-           "libsc" => "./t8code-local/prefix/lib/libsc.so", force = true)
+           "libsc" => abspath("./t8code-local/prefix/lib/libsc.so"), force = true)
 
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1

From 3311616c76d57cce8d6bb14a01a834159b49ecf8 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 16:31:57 +0200
Subject: [PATCH 40/45] add a precompile step

---
 .github/workflows/test.yml | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 11a827f..72593ff 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -183,6 +183,13 @@ jobs:
            UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
            "libsc" => abspath("./t8code-local/prefix/lib/libsc.so"), force = true)
 
+      - name: Precompile
+        if: matrix.mpi-provider == 'SYSTEM_MPI'
+        shell: julia --color=yes --project=. {0}
+        run: |
+          using Pkg
+          Pkg.precompile(; skip_dependents=false)
+
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1
 

From 0f6fb94e83eda4120a8be625c262d58554f49fa8 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 16:46:46 +0200
Subject: [PATCH 41/45] separate handling of julia nightly

---
 .github/workflows/test.yml | 13 ++++++++++++-
 1 file changed, 12 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 72593ff..f05d489 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -183,12 +183,23 @@ jobs:
            UUID("d0cc0030-9a40-4274-8435-baadcfd54fa1"), # UUID of T8code.jl
            "libsc" => abspath("./t8code-local/prefix/lib/libsc.so"), force = true)
 
+      # Add an explicit precompile step where we expect t8code_jll to fail
+      # https://github.com/DLR-AMR/T8code.jl/pull/143#issuecomment-5783271942
+      - name: Precompile (nightly)
+        if: matrix.mpi-provider == 'SYSTEM_MPI' && matrix.julia-version == 'nightly'
+        shell: julia --color=yes --project=. {0}
+        run: |
+          using Pkg
+          Pkg.precompile()
+        continue-on-error: true
+
       - name: Precompile
-        if: matrix.mpi-provider == 'SYSTEM_MPI'
+        if: matrix.mpi-provider == 'SYSTEM_MPI' && matrix.julia-version != 'nightly'
         shell: julia --color=yes --project=. {0}
         run: |
           using Pkg
           Pkg.precompile(; skip_dependents=false)
+        continue-on-error: true
 
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1

From 0529b425702195ca9edbebc6173684c4ce37ac2b Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 17:16:32 +0200
Subject: [PATCH 42/45] duh

---
 .github/workflows/test.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f05d489..36184ae 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -190,7 +190,7 @@ jobs:
         shell: julia --color=yes --project=. {0}
         run: |
           using Pkg
-          Pkg.precompile()
+          Pkg.precompile(; skip_dependents=false)
         continue-on-error: true
 
       - name: Precompile
@@ -198,7 +198,7 @@ jobs:
         shell: julia --color=yes --project=. {0}
         run: |
           using Pkg
-          Pkg.precompile(; skip_dependents=false)
+          Pkg.precompile()
         continue-on-error: true
 
       - name: Run Julia tests

From b247dac08b2800af33bcfb242db9f707d1c92bcd Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Wed, 23 Sep 2026 17:28:33 +0200
Subject: [PATCH 43/45] prevent precompiling again

---
 .github/workflows/test.yml | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index 36184ae..a7482dd 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -203,6 +203,8 @@ jobs:
 
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1
+        env:
+          JULIA_PKG_PRECOMPILE_AUTO: 0
 
       # Enable tmate debugging of manually-triggered workflows if the input option was provided
       - name: Setup tmate session

From c37eb1b720a467cfc2265692adaac86df7407695 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Thu, 24 Sep 2026 06:51:57 +0200
Subject: [PATCH 44/45] flags as in runtest

---
 .github/workflows/test.yml | 6 ++----
 1 file changed, 2 insertions(+), 4 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index a7482dd..f22cd62 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -187,7 +187,7 @@ jobs:
       # https://github.com/DLR-AMR/T8code.jl/pull/143#issuecomment-5783271942
       - name: Precompile (nightly)
         if: matrix.mpi-provider == 'SYSTEM_MPI' && matrix.julia-version == 'nightly'
-        shell: julia --color=yes --project=. {0}
+        shell: julia --color=yes --check-bounds=yes --compiled-modules=yes --depwarn=yes--project=. {0}
         run: |
           using Pkg
           Pkg.precompile(; skip_dependents=false)
@@ -195,7 +195,7 @@ jobs:
 
       - name: Precompile
         if: matrix.mpi-provider == 'SYSTEM_MPI' && matrix.julia-version != 'nightly'
-        shell: julia --color=yes --project=. {0}
+        shell: julia --color=yes --check-bounds=yes --compiled-modules=yes --depwarn=yes--project=. {0}
         run: |
           using Pkg
           Pkg.precompile()
@@ -203,8 +203,6 @@ jobs:
 
       - name: Run Julia tests
         uses: julia-actions/julia-runtest@v1
-        env:
-          JULIA_PKG_PRECOMPILE_AUTO: 0
 
       # Enable tmate debugging of manually-triggered workflows if the input option was provided
       - name: Setup tmate session

From 04da502235cb3f452c89f7e70a5eadf0fb82fd47 Mon Sep 17 00:00:00 2001
From: Benedict Geihe <bgeihe@uni-koeln.de>
Date: Thu, 24 Sep 2026 07:43:42 +0200
Subject: [PATCH 45/45] even more args

---
 .github/workflows/test.yml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index f22cd62..eed19b4 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -187,7 +187,7 @@ jobs:
       # https://github.com/DLR-AMR/T8code.jl/pull/143#issuecomment-5783271942
       - name: Precompile (nightly)
         if: matrix.mpi-provider == 'SYSTEM_MPI' && matrix.julia-version == 'nightly'
-        shell: julia --color=yes --check-bounds=yes --compiled-modules=yes --depwarn=yes--project=. {0}
+        shell: julia --code-coverage=@/home/runner/work/T8code.jl/T8code.jl --color=yes --warn-overwrite=yes --depwarn=yes --inline=yes --startup-file=no --track-allocation=none --check-bounds=yes --compiled-modules=yes --depwarn=yes --project=. {0}
         run: |
           using Pkg
           Pkg.precompile(; skip_dependents=false)
@@ -195,7 +195,7 @@ jobs:
 
       - name: Precompile
         if: matrix.mpi-provider == 'SYSTEM_MPI' && matrix.julia-version != 'nightly'
-        shell: julia --color=yes --check-bounds=yes --compiled-modules=yes --depwarn=yes--project=. {0}
+        shell: julia --code-coverage=@/home/runner/work/T8code.jl/T8code.jl --color=yes --warn-overwrite=yes --depwarn=yes --inline=yes --startup-file=no --track-allocation=none --check-bounds=yes --compiled-modules=yes --depwarn=yes --project=. {0}
         run: |
           using Pkg
           Pkg.precompile()