SciML · ChrisRackauckas · Jun 8, 2026 · Jun 7, 2026 · Jun 7, 2026 · Jun 7, 2026
diff --git a/.github/workflows/CI.yml b/.github/workflows/CI.yml
@@ -18,10 +18,22 @@ jobs:
     strategy:
       fail-fast: false
       matrix:
+        # Only the root umbrella package's own test groups are listed here.
+        # The lib/* sublibraries are covered by SublibraryCI.yml (project model);
+        # they are intentionally not re-tested through the root matrix.
+        group:
+          - Core
+          - QA
         version:
-          - "1"
           - "lts"
+          - "1"
+          - "pre"
+        exclude:
+          # QA (explicit-imports check) does not need the pre-release Julia.
+          - group: QA
+            version: "pre"
     uses: "SciML/.github/.github/workflows/tests.yml@v1"
     with:
       julia-version: "${{ matrix.version }}"
+      group: "${{ matrix.group }}"
     secrets: "inherit"
diff --git a/.github/workflows/Downgrade.yml b/.github/workflows/Downgrade.yml
@@ -10,14 +10,13 @@ on:
       - master
     paths-ignore:
       - 'docs/**'
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
 jobs:
   downgrade:
     name: "Downgrade"
-    strategy:
-      matrix:
-        julia-version: ['1.10']
     uses: "SciML/.github/.github/workflows/downgrade.yml@v1"
     with:
-      julia-version: "${{ matrix.julia-version }}"
-      skip: "Pkg,TOML"
+      group: "Core"
     secrets: "inherit"
diff --git a/.github/workflows/DowngradeSublibraries.yml b/.github/workflows/DowngradeSublibraries.yml
@@ -18,5 +18,6 @@ jobs:
     uses: "SciML/.github/.github/workflows/sublibrary-downgrade.yml@v1"
     secrets: "inherit"
     with:
-      julia-version: "lts"
-      skip: "Pkg,TOML,Statistics,LinearAlgebra,SparseArrays,InteractiveUtils,Random,Test,Markdown"
+      group-env-name: "DIFFEQPROBLEMLIBRARY_TEST_GROUP"
+      group-env-value: "Core"
+      # Every lib/* sublibrary is downgrade-tested (projects auto-discovered, no exclusions).
diff --git a/.github/workflows/Downstream.yml b/.github/workflows/Downstream.yml
@@ -0,0 +1,53 @@
+name: IntegrationTest
+on:
+  push:
+    branches: [master]
+    tags: [v*]
+  pull_request:
+concurrency:
+  group: ${{ github.workflow }}-${{ github.ref }}
+  cancel-in-progress: ${{ startsWith(github.ref, 'refs/pull/') }}
+jobs:
+  test:
+    name: ${{ matrix.package.repo }}/${{ matrix.package.group }}/${{ matrix.julia-version }}
+    runs-on: ${{ matrix.os }}
+    env:
+      GROUP: ${{ matrix.package.group }}
+    strategy:
+      fail-fast: false
+      matrix:
+        julia-version: ['1.10']
+        os: [ubuntu-latest]
+        package:
+          - {user: SciML, repo: DiffEqDevTools.jl, group: All}
+          - {user: SciML, repo: OrdinaryDiffEq.jl, group: Regression_I}
+    steps:
+      - uses: actions/checkout@v6
+      - uses: julia-actions/setup-julia@v3
+        with:
+          version: ${{ matrix.julia-version }}
+          arch: x64
+      - name: Clone Downstream
+        uses: actions/checkout@v6
+        with:
+          repository: ${{ matrix.package.user }}/${{ matrix.package.repo }}
+          path: downstream
+      - name: Load this and run the downstream tests
+        shell: julia --color=yes --project=downstream {0}
+        run: |
+          using Pkg
+          try
+            Pkg.develop(map(path ->Pkg.PackageSpec.(;path="lib/$(path)"), readdir("./lib")));
+            Pkg.test(coverage=true)
+          catch err
+            err isa Pkg.Resolve.ResolverError || rethrow()
+            @info "Not compatible with this release. No problem." exception=err
+            exit(0)
+          end
+      - uses: julia-actions/julia-processcoverage@v1
+      - uses: codecov/codecov-action@v6
+        with:
+          token: ${{ secrets.CODECOV_TOKEN }}
+          files: lcov.info
+          fail_ci_if_error: false
+          disable_safe_directory: true
diff --git a/.github/workflows/SublibraryCI.yml b/.github/workflows/SublibraryCI.yml
@@ -19,4 +19,7 @@ concurrency:
 jobs:
   sublibraries:
     uses: "SciML/.github/.github/workflows/sublibrary-project-tests.yml@v1"
+    with:
+      group-env-name: DIFFEQPROBLEMLIBRARY_TEST_GROUP
+      check-bounds: auto
     secrets: "inherit"
diff --git a/.github/workflows/TagBot.yml b/.github/workflows/TagBot.yml
@@ -1,15 +1,26 @@
-name: TagBot
+name: "TagBot"
 on:
   issue_comment:
-    types:
-      - created
+    types: [created]
   workflow_dispatch:
 jobs:
-  TagBot:
-    if: github.event_name == 'workflow_dispatch' || github.actor == 'JuliaTagBot'
-    runs-on: ubuntu-latest
-    steps:
-      - uses: JuliaRegistries/TagBot@v1
-        with:
-          token: ${{ secrets.GITHUB_TOKEN }}
-          ssh: ${{ secrets.DOCUMENTER_KEY }}
+  tagbot:
+    uses: "SciML/.github/.github/workflows/tagbot.yml@v1"
+    secrets: "inherit"
+
+  tagbot-subpackages:
+    strategy:
+      fail-fast: false
+      matrix:
+        subdir:
+          - "lib/BVProblemLibrary"
+          - "lib/DAEProblemLibrary"
+          - "lib/DDEProblemLibrary"
+          - "lib/JumpProblemLibrary"
+          - "lib/NonlinearProblemLibrary"
+          - "lib/ODEProblemLibrary"
+          - "lib/SDEProblemLibrary"
+    uses: "SciML/.github/.github/workflows/tagbot.yml@v1"
+    with:
+      subdir: "${{ matrix.subdir }}"
+    secrets: "inherit"
diff --git a/Project.toml b/Project.toml
@@ -12,19 +12,31 @@ NonlinearProblemLibrary = "b7050fa9-e91f-4b37-bcee-a89a063da141"
 ODEProblemLibrary = "fdc4e326-1af4-4b90-96e7-779fcce2daa5"
 SDEProblemLibrary = "c72e72a9-a271-4b2b-8966-303ed956772e"
 
+[sources]
+BVProblemLibrary = {path = "lib/BVProblemLibrary"}
+DAEProblemLibrary = {path = "lib/DAEProblemLibrary"}
+DDEProblemLibrary = {path = "lib/DDEProblemLibrary"}
+JumpProblemLibrary = {path = "lib/JumpProblemLibrary"}
+NonlinearProblemLibrary = {path = "lib/NonlinearProblemLibrary"}
+ODEProblemLibrary = {path = "lib/ODEProblemLibrary"}
+SDEProblemLibrary = {path = "lib/SDEProblemLibrary"}
+
 [compat]
 BVProblemLibrary = "0.1"
 DAEProblemLibrary = "0.1"
 DDEProblemLibrary = "0.1"
 JumpProblemLibrary = "1, 2.0"
 NonlinearProblemLibrary = "0.1"
 ODEProblemLibrary = "1"
+SafeTestsets = "0.1"
 SDEProblemLibrary = "1"
+Test = "1.10"
 julia = "1.10"
 
 [extras]
-ExplicitImports = "7d51a73a-1435-4ff3-83d9-f097790105c7"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["ExplicitImports", "Test"]
+test = ["Pkg", "SafeTestsets", "Test"]
diff --git a/lib/BVProblemLibrary/LICENSE → lib/BVProblemLibrary/LICENSE.md b/lib/BVProblemLibrary/LICENSE → lib/BVProblemLibrary/LICENSE.md
diff --git a/lib/BVProblemLibrary/Project.toml b/lib/BVProblemLibrary/Project.toml
@@ -8,14 +8,17 @@ Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 SpecialFunctions = "276daf66-3868-5448-9aa4-cd146d93841b"
 
 [compat]
-Aqua = "0.8"
 DiffEqBase = "6, 7"
 Markdown = "1.10"
+SafeTestsets = "0.1"
 SpecialFunctions = "2.3"
+Test = "1.10"
 julia = "1.10"
 
 [extras]
-Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua"]
+test = ["Pkg", "SafeTestsets", "Test"]
diff --git a/lib/BVProblemLibrary/README.md b/lib/BVProblemLibrary/README.md
@@ -0,0 +1,10 @@
+# BVProblemLibrary.jl
+
+[![Join the chat at https://julialang.zulipchat.com #sciml-bridged](https://img.shields.io/static/v1?label=Zulip&message=chat&color=9558b2&labelColor=389826)](https://julialang.zulipchat.com/#narrow/stream/279055-sciml-bridged)
+[![Global Docs](https://img.shields.io/badge/docs-SciML-blue.svg)](https://docs.sciml.ai/DiffEqDocs/stable/)
+
+[![ColPrac: Contributor's Guide on Collaborative Practices for Community Packages](https://img.shields.io/badge/ColPrac-Contributor%27s%20Guide-blueviolet)](https://github.com/SciML/ColPrac)
+[![SciML Code Style](https://img.shields.io/static/v1?label=code%20style&message=SciML&color=9558b2&labelColor=389826)](https://github.com/SciML/SciMLStyle)
+
+BVProblemLibrary.jl is a component of the [DiffEqProblemLibrary.jl](https://github.com/SciML/DiffEqProblemLibrary.jl) monorepo. A library of premade boundary value problems (BVProblems) for testing and benchmarking boundary value differential equation solvers.
+While completely independent and usable on its own, users wanting the full set of premade differential equation problems should use [DiffEqProblemLibrary.jl](https://github.com/SciML/DiffEqProblemLibrary.jl).
diff --git a/lib/BVProblemLibrary/test/qa/Project.toml b/lib/BVProblemLibrary/test/qa/Project.toml
@@ -0,0 +1,13 @@
+[deps]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+BVProblemLibrary = "ded0fc24-dfea-4565-b1d9-79c027d14d84"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[sources]
+BVProblemLibrary = {path = "../.."}
+
+[compat]
+Aqua = "0.8"
+BVProblemLibrary = "0.1"
+Test = "1.10"
+julia = "1.10"
diff --git a/lib/BVProblemLibrary/test/qa/qa.jl b/lib/BVProblemLibrary/test/qa/qa.jl
@@ -0,0 +1,6 @@
+using BVProblemLibrary
+using Aqua
+
+@testset "Aqua" begin
+    Aqua.test_all(BVProblemLibrary; ambiguities = false)
+end
diff --git a/lib/BVProblemLibrary/test/runtests.jl b/lib/BVProblemLibrary/test/runtests.jl
@@ -1,8 +1,24 @@
-# The test is simply that all of the examples build!
+using Pkg
 using BVProblemLibrary
+using SafeTestsets, Test
 
-# Check that there are no undefined exports, stale dependencies, etc.
-# Ambiguity checks are disabled since tests fail due to ambiguities
-# in dependencies
-using Aqua
-Aqua.test_all(BVProblemLibrary; ambiguities = false)
+const TEST_GROUP = get(ENV, "DIFFEQPROBLEMLIBRARY_TEST_GROUP", "All")
+
+function activate_qa_env()
+    Pkg.activate(joinpath(@__DIR__, "qa"))
+    return Pkg.instantiate()
+end
+
+# The Core test is simply that all of the examples build (load the module).
+if TEST_GROUP == "Core" || TEST_GROUP == "All"
+    @time @testset "Load Tests" begin
+        @test BVProblemLibrary isa Module
+    end
+end
+
+# Quality assurance: no undefined exports, stale dependencies, etc.
+# Ambiguity checks are disabled since tests fail due to ambiguities in dependencies.
+if TEST_GROUP == "QA" || TEST_GROUP == "All"
+    activate_qa_env()
+    @time @safetestset "Aqua" include("qa/qa.jl")
+end
diff --git a/lib/BVProblemLibrary/test/test_groups.toml b/lib/BVProblemLibrary/test/test_groups.toml
@@ -0,0 +1,5 @@
+[Core]
+versions = ["lts", "1", "pre"]
+
+[QA]
+versions = ["lts", "1"]
diff --git a/lib/DAEProblemLibrary/LICENSE → lib/DAEProblemLibrary/LICENSE.md b/lib/DAEProblemLibrary/LICENSE → lib/DAEProblemLibrary/LICENSE.md
diff --git a/lib/DAEProblemLibrary/Project.toml b/lib/DAEProblemLibrary/Project.toml
@@ -7,13 +7,16 @@ DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 Markdown = "d6f4376e-aef5-505a-96c1-9c027394607a"
 
 [compat]
-Aqua = "0.8"
 DiffEqBase = "6, 7"
 Markdown = "1.10"
+SafeTestsets = "0.1"
+Test = "1.10"
 julia = "1.10"
 
 [extras]
-Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua"]
+test = ["Pkg", "SafeTestsets", "Test"]
diff --git a/lib/DAEProblemLibrary/README.md b/lib/DAEProblemLibrary/README.md
@@ -0,0 +1,10 @@
+# DAEProblemLibrary.jl
+
+[![Join the chat at https://julialang.zulipchat.com #sciml-bridged](https://img.shields.io/static/v1?label=Zulip&message=chat&color=9558b2&labelColor=389826)](https://julialang.zulipchat.com/#narrow/stream/279055-sciml-bridged)
+[![Global Docs](https://img.shields.io/badge/docs-SciML-blue.svg)](https://docs.sciml.ai/DiffEqDocs/stable/)
+
+[![ColPrac: Contributor's Guide on Collaborative Practices for Community Packages](https://img.shields.io/badge/ColPrac-Contributor%27s%20Guide-blueviolet)](https://github.com/SciML/ColPrac)
+[![SciML Code Style](https://img.shields.io/static/v1?label=code%20style&message=SciML&color=9558b2&labelColor=389826)](https://github.com/SciML/SciMLStyle)
+
+DAEProblemLibrary.jl is a component of the [DiffEqProblemLibrary.jl](https://github.com/SciML/DiffEqProblemLibrary.jl) monorepo. A library of premade differential-algebraic equation problems (DAEProblems) for testing and benchmarking DAE solvers.
+While completely independent and usable on its own, users wanting the full set of premade differential equation problems should use [DiffEqProblemLibrary.jl](https://github.com/SciML/DiffEqProblemLibrary.jl).
diff --git a/lib/DAEProblemLibrary/test/qa/Project.toml b/lib/DAEProblemLibrary/test/qa/Project.toml
@@ -0,0 +1,13 @@
+[deps]
+Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+DAEProblemLibrary = "dfb8ca35-80a1-48ba-a605-84916a45b4f8"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
+
+[sources]
+DAEProblemLibrary = {path = "../.."}
+
+[compat]
+Aqua = "0.8"
+DAEProblemLibrary = "0.1"
+Test = "1.10"
+julia = "1.10"
diff --git a/lib/DAEProblemLibrary/test/qa/qa.jl b/lib/DAEProblemLibrary/test/qa/qa.jl
@@ -0,0 +1,6 @@
+using DAEProblemLibrary
+using Aqua
+
+@testset "Aqua" begin
+    Aqua.test_all(DAEProblemLibrary; ambiguities = false)
+end
diff --git a/lib/DAEProblemLibrary/test/runtests.jl b/lib/DAEProblemLibrary/test/runtests.jl
@@ -1,8 +1,24 @@
-# The test is simply that all of the examples build!
+using Pkg
 using DAEProblemLibrary
+using SafeTestsets, Test
 
-# Check that there are no undefined exports, stale dependencies, etc.
-# Ambiguity checks are disabled since tests fail due to ambiguities
-# in dependencies
-using Aqua
-Aqua.test_all(DAEProblemLibrary; ambiguities = false)
+const TEST_GROUP = get(ENV, "DIFFEQPROBLEMLIBRARY_TEST_GROUP", "All")
+
+function activate_qa_env()
+    Pkg.activate(joinpath(@__DIR__, "qa"))
+    return Pkg.instantiate()
+end
+
+# The Core test is simply that all of the examples build (load the module).
+if TEST_GROUP == "Core" || TEST_GROUP == "All"
+    @time @testset "Load Tests" begin
+        @test DAEProblemLibrary isa Module
+    end
+end
+
+# Quality assurance: no undefined exports, stale dependencies, etc.
+# Ambiguity checks are disabled since tests fail due to ambiguities in dependencies.
+if TEST_GROUP == "QA" || TEST_GROUP == "All"
+    activate_qa_env()
+    @time @safetestset "Aqua" include("qa/qa.jl")
+end
diff --git a/lib/DAEProblemLibrary/test/test_groups.toml b/lib/DAEProblemLibrary/test/test_groups.toml
@@ -0,0 +1,5 @@
+[Core]
+versions = ["lts", "1", "pre"]
+
+[QA]
+versions = ["lts", "1"]
diff --git a/lib/DDEProblemLibrary/LICENSE → lib/DDEProblemLibrary/LICENSE.md b/lib/DDEProblemLibrary/LICENSE → lib/DDEProblemLibrary/LICENSE.md
diff --git a/lib/DDEProblemLibrary/Project.toml b/lib/DDEProblemLibrary/Project.toml
@@ -6,12 +6,15 @@ version = "0.1.5"
 DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 
 [compat]
-Aqua = "0.8"
 DiffEqBase = "6, 7"
+SafeTestsets = "0.1"
+Test = "1.10"
 julia = "1.10"
 
 [extras]
-Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
+Pkg = "44cfe95a-1eb2-52ea-b672-e2afdf69b78f"
+SafeTestsets = "1bc83da4-3b8d-516f-aca4-4fe02f6d838f"
+Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [targets]
-test = ["Aqua"]
+test = ["Pkg", "SafeTestsets", "Test"]
diff --git a/lib/DDEProblemLibrary/README.md b/lib/DDEProblemLibrary/README.md
@@ -0,0 +1,10 @@
+# DDEProblemLibrary.jl
+
+[![Join the chat at https://julialang.zulipchat.com #sciml-bridged](https://img.shields.io/static/v1?label=Zulip&message=chat&color=9558b2&labelColor=389826)](https://julialang.zulipchat.com/#narrow/stream/279055-sciml-bridged)
+[![Global Docs](https://img.shields.io/badge/docs-SciML-blue.svg)](https://docs.sciml.ai/DiffEqDocs/stable/)
+
+[![ColPrac: Contributor's Guide on Collaborative Practices for Community Packages](https://img.shields.io/badge/ColPrac-Contributor%27s%20Guide-blueviolet)](https://github.com/SciML/ColPrac)
+[![SciML Code Style](https://img.shields.io/static/v1?label=code%20style&message=SciML&color=9558b2&labelColor=389826)](https://github.com/SciML/SciMLStyle)
+
+DDEProblemLibrary.jl is a component of the [DiffEqProblemLibrary.jl](https://github.com/SciML/DiffEqProblemLibrary.jl) monorepo. A library of premade delay differential equation problems (DDEProblems) for testing and benchmarking delay differential equation solvers.
+While completely independent and usable on its own, users wanting the full set of premade differential equation problems should use [DiffEqProblemLibrary.jl](https://github.com/SciML/DiffEqProblemLibrary.jl).