From bb359cd34db30fc0ffe2bc68d0f10cd927319763 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 08:50:50 +0100
Subject: [PATCH 01/39] remove restriction of DiffEqBase.jl (used as hotfix)

---
 .github/workflows/Downgrade.yml | 2 +-
 Project.toml                    | 2 --
 2 files changed, 1 insertion(+), 3 deletions(-)

diff --git a/.github/workflows/Downgrade.yml b/.github/workflows/Downgrade.yml
index 78492151a67..85f4625d275 100644
--- a/.github/workflows/Downgrade.yml
+++ b/.github/workflows/Downgrade.yml
@@ -72,7 +72,7 @@ jobs:
       - uses: julia-actions/cache@v2
       - uses: julia-actions/julia-downgrade-compat@v1
         with:
-          skip: LinearAlgebra,Printf,SparseArrays,UUIDs,DiffEqBase,DelimitedFiles,Test,Downloads,Random
+          skip: LinearAlgebra,Printf,SparseArrays,UUIDs,DelimitedFiles,Test,Downloads,Random
           projects: ., test
       - uses: julia-actions/julia-buildpkg@v1
         env:
diff --git a/Project.toml b/Project.toml
index 95d3c42d395..1fd17016bc6 100644
--- a/Project.toml
+++ b/Project.toml
@@ -9,7 +9,6 @@ CodeTracking = "da1fd8a2-8d9e-5ec2-8556-3022fb5608a2"
 ConstructionBase = "187b0558-2788-49d3-abe0-74a17ed4e7c9"
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
-DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 DiffEqCallbacks = "459566f4-90b8-5000-8ac3-15dfb0a30def"
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
 EllipsisNotation = "da5c29d0-fa7d-589e-88eb-ea29b0a81949"
@@ -69,7 +68,6 @@ ConstructionBase = "1.5"
 Convex = "0.16"
 DataStructures = "0.18.15"
 DelimitedFiles = "1"
-DiffEqBase = "6 - 6.143"
 DiffEqCallbacks = "2.35"
 Downloads = "1.6"
 ECOS = "1.1.2"

From 7ca0e1f82c2eebe2e1c6a77c114f0f0a0cd33415 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 09:02:19 +0100
Subject: [PATCH 02/39] ODE_DEFAULT_NORM moved

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

diff --git a/test/test_mpi.jl b/test/test_mpi.jl
index 001d9bff86e..66c5281089a 100644
--- a/test/test_mpi.jl
+++ b/test/test_mpi.jl
@@ -34,13 +34,13 @@ end # MPI
 
     t = 0.5
     let u = 1.0
-        @test ode_norm(u, t) ≈ OrdinaryDiffEq.ODE_DEFAULT_NORM(u, t)
+        @test ode_norm(u, t) ≈ OrdinaryDiffEq.DiffEqBase.ODE_DEFAULT_NORM(u, t)
     end
     let u = [1.0, -2.0]
-        @test ode_norm(u, t) ≈ OrdinaryDiffEq.ODE_DEFAULT_NORM(u, t)
+        @test ode_norm(u, t) ≈ OrdinaryDiffEq.DiffEqBase.ODE_DEFAULT_NORM(u, t)
     end
     let u = [SVector(1.0, -2.0), SVector(0.5, -0.1)]
-        @test ode_norm(u, t) ≈ OrdinaryDiffEq.ODE_DEFAULT_NORM(u, t)
+        @test ode_norm(u, t) ≈ OrdinaryDiffEq.DiffEqBase.ODE_DEFAULT_NORM(u, t)
     end
 end # MPI supporting functionality
 

From 74a94433745965abb4c82b0510bc1c7f177eaaf2 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 09:26:26 +0100
Subject: [PATCH 03/39] use ADTypes

---
 examples/tree_1d_dgsem/elixir_advection_diffusion.jl         | 4 ++--
 examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl | 4 ++--
 test/Project.toml                                            | 2 ++
 test/test_parabolic_1d.jl                                    | 2 +-
 4 files changed, 7 insertions(+), 5 deletions(-)

diff --git a/examples/tree_1d_dgsem/elixir_advection_diffusion.jl b/examples/tree_1d_dgsem/elixir_advection_diffusion.jl
index 94d1da9132b..82c43dd6da8 100644
--- a/examples/tree_1d_dgsem/elixir_advection_diffusion.jl
+++ b/examples/tree_1d_dgsem/elixir_advection_diffusion.jl
@@ -1,4 +1,4 @@
-using OrdinaryDiffEq
+using OrdinaryDiffEq, ADTypes
 using Trixi
 
 ###############################################################################
@@ -87,7 +87,7 @@ callbacks = CallbackSet(summary_callback, analysis_callback, alive_callback, sav
 # OrdinaryDiffEq's `solve` method evolves the solution in time and executes the passed callbacks
 time_int_tol = 1.0e-10
 time_abs_tol = 1.0e-10
-sol = solve(ode, KenCarp4(autodiff = false), abstol = time_abs_tol, reltol = time_int_tol,
+sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()), abstol = time_abs_tol, reltol = time_int_tol,
             save_everystep = false, callback = callbacks)
 
 # Print the timer summary
diff --git a/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl b/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
index 1aab3308fab..763187009dc 100644
--- a/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
+++ b/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
@@ -1,4 +1,4 @@
-using OrdinaryDiffEq
+using OrdinaryDiffEq, ADTypes
 using Trixi
 
 ###############################################################################
@@ -22,7 +22,7 @@ callbacks = CallbackSet(summary_callback, analysis_callback, alive_callback)
 ###############################################################################
 # run the simulation
 
-sol = solve(ode, KenCarp4(autodiff = false), abstol = time_abs_tol, reltol = time_int_tol,
+sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()), abstol = time_abs_tol, reltol = time_int_tol,
             save_everystep = false, callback = callbacks)
 
 # Print the timer summary
diff --git a/test/Project.toml b/test/Project.toml
index fb7eeb1a80c..9c5f639828b 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -1,4 +1,5 @@
 [deps]
+ADTypes = "47edcb42-4c32-4615-8424-f2b9edc5f35b"
 Aqua = "4c88cf16-eb10-579e-8560-4a9242c79595"
 CairoMakie = "13f3f980-e62b-5c42-98c6-ff1f3baf88f0"
 Convex = "f65535da-76fb-5f13-bab9-19810c17039a"
@@ -21,6 +22,7 @@ StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
+ADTypes = "1.12"
 Aqua = "0.8"
 CairoMakie = "0.12, 0.13"
 Convex = "0.16"
diff --git a/test/test_parabolic_1d.jl b/test/test_parabolic_1d.jl
index 49cf359c51d..4b9b93121f8 100644
--- a/test/test_parabolic_1d.jl
+++ b/test/test_parabolic_1d.jl
@@ -60,7 +60,7 @@ end
     # Create a CallbackSet to collect all callbacks such that they can be passed to the ODE solver
     callbacks = CallbackSet(summary_callback, analysis_callback, alive_callback,
                             amr_callback)
-    sol = solve(ode, KenCarp4(autodiff = false), abstol = time_abs_tol,
+    sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()), abstol = time_abs_tol,
                 reltol = time_int_tol,
                 save_everystep = false, callback = callbacks)
     l2_error, linf_error = analysis_callback(sol)

From b6b507dd117530ab4ff24aa03d39745e57d7e9a2 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 09:31:15 +0100
Subject: [PATCH 04/39] fix another depwarn

---
 examples/tree_3d_dgsem/elixir_lbm_taylor_green_vortex.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/tree_3d_dgsem/elixir_lbm_taylor_green_vortex.jl b/examples/tree_3d_dgsem/elixir_lbm_taylor_green_vortex.jl
index df034af1bc9..56d2bc01491 100644
--- a/examples/tree_3d_dgsem/elixir_lbm_taylor_green_vortex.jl
+++ b/examples/tree_3d_dgsem/elixir_lbm_taylor_green_vortex.jl
@@ -73,5 +73,5 @@ callbacks = CallbackSet(summary_callback,
 sol = solve(ode, CarpenterKennedy2N54(williamson_condition = false),
             dt = 1.0, # solve needs some value here but it will be overwritten by the stepsize_callback
             save_everystep = false, callback = callbacks,
-            save_start = false, alias_u0 = true);
+            save_start = false, alias = ODEAliasSpecifier(alias_u0 = true));
 summary_callback() # print the timer summary

From a719514a452f2ef053768add88693b5d7ad5d365 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 09:31:49 +0100
Subject: [PATCH 05/39] bump DiffEqCallbacks

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

diff --git a/Project.toml b/Project.toml
index 1fd17016bc6..6bc4dae56ee 100644
--- a/Project.toml
+++ b/Project.toml
@@ -68,7 +68,7 @@ ConstructionBase = "1.5"
 Convex = "0.16"
 DataStructures = "0.18.15"
 DelimitedFiles = "1"
-DiffEqCallbacks = "2.35"
+DiffEqCallbacks = "2.35, 4"
 Downloads = "1.6"
 ECOS = "1.1.2"
 EllipsisNotation = "1.0"

From 9b4763f042104fd773899e835464d5efd6579749 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 09:34:09 +0100
Subject: [PATCH 06/39] format

---
 examples/tree_1d_dgsem/elixir_advection_diffusion.jl         | 3 ++-
 examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl | 3 ++-
 test/test_parabolic_1d.jl                                    | 4 ++--
 3 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/examples/tree_1d_dgsem/elixir_advection_diffusion.jl b/examples/tree_1d_dgsem/elixir_advection_diffusion.jl
index 82c43dd6da8..95e94ca21f1 100644
--- a/examples/tree_1d_dgsem/elixir_advection_diffusion.jl
+++ b/examples/tree_1d_dgsem/elixir_advection_diffusion.jl
@@ -87,7 +87,8 @@ callbacks = CallbackSet(summary_callback, analysis_callback, alive_callback, sav
 # OrdinaryDiffEq's `solve` method evolves the solution in time and executes the passed callbacks
 time_int_tol = 1.0e-10
 time_abs_tol = 1.0e-10
-sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()), abstol = time_abs_tol, reltol = time_int_tol,
+sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()),
+            abstol = time_abs_tol, reltol = time_int_tol,
             save_everystep = false, callback = callbacks)
 
 # Print the timer summary
diff --git a/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl b/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
index 763187009dc..b16963762fd 100644
--- a/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
+++ b/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
@@ -22,7 +22,8 @@ callbacks = CallbackSet(summary_callback, analysis_callback, alive_callback)
 ###############################################################################
 # run the simulation
 
-sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()), abstol = time_abs_tol, reltol = time_int_tol,
+sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()),
+            abstol = time_abs_tol, reltol = time_int_tol,
             save_everystep = false, callback = callbacks)
 
 # Print the timer summary
diff --git a/test/test_parabolic_1d.jl b/test/test_parabolic_1d.jl
index 4b9b93121f8..72e3b19a9c7 100644
--- a/test/test_parabolic_1d.jl
+++ b/test/test_parabolic_1d.jl
@@ -60,8 +60,8 @@ end
     # Create a CallbackSet to collect all callbacks such that they can be passed to the ODE solver
     callbacks = CallbackSet(summary_callback, analysis_callback, alive_callback,
                             amr_callback)
-    sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()), abstol = time_abs_tol,
-                reltol = time_int_tol,
+    sol = solve(ode, KenCarp4(autodiff = AutoFiniteDiff()),
+                abstol = time_abs_tol, reltol = time_int_tol,
                 save_everystep = false, callback = callbacks)
     l2_error, linf_error = analysis_callback(sol)
     @test l2_error ≈ [6.4878111416468355e-6]

From 286e786d587b205578e481d937e41b616b3117e0 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 09:38:04 +0100
Subject: [PATCH 07/39] allow older version of ADTypes

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

diff --git a/test/Project.toml b/test/Project.toml
index 9c5f639828b..275bb8fb183 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -22,7 +22,7 @@ StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
-ADTypes = "1.12"
+ADTypes = "0.2, 1.12"
 Aqua = "0.8"
 CairoMakie = "0.12, 0.13"
 Convex = "0.16"

From ac03d56262372b128c39d207adf9e5d6029d2cc5 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <ranocha@users.noreply.github.com>
Date: Fri, 7 Feb 2025 10:02:42 +0100
Subject: [PATCH 08/39] Update test/Project.toml

Co-authored-by: Joshua Lampert <51029046+JoshuaLampert@users.noreply.github.com>
---
 test/Project.toml | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/test/Project.toml b/test/Project.toml
index 275bb8fb183..26bbad99907 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -22,7 +22,7 @@ StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
-ADTypes = "0.2, 1.12"
+ADTypes = "0.2.5, 1.12"
 Aqua = "0.8"
 CairoMakie = "0.12, 0.13"
 Convex = "0.16"

From a750d7d742a5a12443e1c0b1e9dd40d7d2f80dbd Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 10:29:09 +0100
Subject: [PATCH 09/39] restrict to ADTypes v1

---
 test/Project.toml | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/test/Project.toml b/test/Project.toml
index 26bbad99907..bcff2f142af 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -22,7 +22,7 @@ StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
-ADTypes = "0.2.5, 1.12"
+ADTypes = "1"
 Aqua = "0.8"
 CairoMakie = "0.12, 0.13"
 Convex = "0.16"
@@ -36,7 +36,7 @@ ForwardDiff = "0.10.24"
 LinearAlgebra = "1"
 MPI = "0.20.6"
 NLsolve = "4.5.1"
-OrdinaryDiffEq = "6.66"
+OrdinaryDiffEq = "6.75"
 Plots = "1.19"
 Printf = "1"
 Quadmath = "0.5.10"

From bbb8cd4271aa7d7d61629290cf39de2c1fbd374d Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 10:32:33 +0100
Subject: [PATCH 10/39] bump ADTypes for NonlinearSolve.jl

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

diff --git a/test/Project.toml b/test/Project.toml
index bcff2f142af..d0c6f0135f2 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -22,7 +22,7 @@ StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
-ADTypes = "1"
+ADTypes = "1.1"
 Aqua = "0.8"
 CairoMakie = "0.12, 0.13"
 Convex = "0.16"

From c4446acc22583a5ba63493d78e37b3938d2578b2 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 11:27:46 +0100
Subject: [PATCH 11/39] fix compat bounds for Downgrade action

---
 Project.toml      | 10 +++++-----
 test/Project.toml |  4 ++--
 2 files changed, 7 insertions(+), 7 deletions(-)

diff --git a/Project.toml b/Project.toml
index 6bc4dae56ee..5049fca387e 100644
--- a/Project.toml
+++ b/Project.toml
@@ -73,7 +73,7 @@ Downloads = "1.6"
 ECOS = "1.1.2"
 EllipsisNotation = "1.0"
 FillArrays = "1.9"
-ForwardDiff = "0.10.24"
+ForwardDiff = "0.10.36"
 HDF5 = "0.16.10, 0.17"
 LinearAlgebra = "1"
 LinearMaps = "2.7, 3.0"
@@ -87,11 +87,11 @@ OffsetArrays = "1.13"
 P4est = "0.4.12"
 Polyester = "0.7.10"
 PrecompileTools = "1.2"
-Preferences = "1.3"
+Preferences = "1.4"
 Printf = "1"
 RecipesBase = "1.3.4"
 RecursiveArrayTools = "3.29"
-Reexport = "1.0"
+Reexport = "1.2"
 Requires = "1.1"
 SciMLBase = "2.67.0"
 SimpleUnPack = "1.1"
@@ -100,12 +100,12 @@ StableRNGs = "1.0.2"
 StartUpDG = "1.1.5"
 Static = "0.8.7, 1"
 StaticArrayInterface = "1.4"
-StaticArrays = "1.7"
+StaticArrays = "1.9"
 StrideArrays = "0.1.26"
 StructArrays = "0.6.18"
 SummationByPartsOperators = "0.5.52"
 T8code = "0.7.4"
-TimerOutputs = "0.5.7"
+TimerOutputs = "0.5.23"
 Triangulate = "2.2"
 TriplotBase = "0.1"
 TriplotRecipes = "0.1"
diff --git a/test/Project.toml b/test/Project.toml
index d0c6f0135f2..f10379628d7 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -32,12 +32,12 @@ Downloads = "1"
 ECOS = "1.1.2"
 ExplicitImports = "1.0.1"
 FFMPEG = "0.4"
-ForwardDiff = "0.10.24"
+ForwardDiff = "0.10.36"
 LinearAlgebra = "1"
 MPI = "0.20.6"
 NLsolve = "4.5.1"
 OrdinaryDiffEq = "6.75"
-Plots = "1.19"
+Plots = "1.26"
 Printf = "1"
 Quadmath = "0.5.10"
 Random = "1"

From c4f5279df9cfa4d8ba5dcfff8b847e6e64608016 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 12:05:24 +0100
Subject: [PATCH 12/39] fix Aqua.jl issue

---
 test/test_aqua.jl | 4 +++-
 1 file changed, 3 insertions(+), 1 deletion(-)

diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index 04c4a533d26..175c4113f23 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -13,7 +13,9 @@ include("test_trixi.jl")
                   # exceptions necessary for adding a new method `StartUpDG.estimate_h`
                   # in src/solvers/dgmulti/sbp.jl
                   piracies = (treat_as_own = [Trixi.StartUpDG.RefElemData,
-                                  Trixi.StartUpDG.MeshData],))
+                                  Trixi.StartUpDG.MeshData],),
+                  # exception necessary because StableRNGs.jl is only used in an extension
+                  stale_deps = (ignore = [StableRNGs]))
     @test isnothing(check_no_implicit_imports(Trixi,
                                               skip = (Core, Base, Trixi.P4est, Trixi.T8code,
                                                       Trixi.EllipsisNotation)))

From b4544731398c2a874a0e88cd5dd9b9f98f43695e Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:11:40 +0100
Subject: [PATCH 13/39] add DiffEqBase extension to fix callback issues with
 custom integrators

---
 Project.toml                                          |  3 +++
 ext/TrixiDiffEqBaseExt.jl                             | 11 +++++++++++
 src/time_integration/methods_2N.jl                    |  8 ++++----
 src/time_integration/methods_3Sstar.jl                |  4 ++--
 src/time_integration/methods_SSP.jl                   |  2 +-
 .../paired_explicit_runge_kutta.jl                    |  6 +++---
 src/time_integration/time_integration.jl              |  3 +++
 7 files changed, 27 insertions(+), 10 deletions(-)
 create mode 100644 ext/TrixiDiffEqBaseExt.jl

diff --git a/Project.toml b/Project.toml
index 5049fca387e..c1c129d7985 100644
--- a/Project.toml
+++ b/Project.toml
@@ -52,11 +52,13 @@ UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 
 [weakdeps]
 Convex = "f65535da-76fb-5f13-bab9-19810c17039a"
+DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 ECOS = "e2685f51-7e38-5353-a97d-a921fd2c8199"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 NLsolve = "2774e3e8-f4cf-5e23-947b-6d7e65073b56"
 
 [extensions]
+TrixiDiffEqBaseExt = "DiffEqBase"
 TrixiConvexECOSExt = ["Convex", "ECOS"]
 TrixiMakieExt = "Makie"
 TrixiNLsolveExt = "NLsolve"
@@ -68,6 +70,7 @@ ConstructionBase = "1.5"
 Convex = "0.16"
 DataStructures = "0.18.15"
 DelimitedFiles = "1"
+DiffEqBase = "6.154"
 DiffEqCallbacks = "2.35, 4"
 Downloads = "1.6"
 ECOS = "1.1.2"
diff --git a/ext/TrixiDiffEqBaseExt.jl b/ext/TrixiDiffEqBaseExt.jl
new file mode 100644
index 00000000000..4737dc978b2
--- /dev/null
+++ b/ext/TrixiDiffEqBaseExt.jl
@@ -0,0 +1,11 @@
+# Package extension for DiffEqBase.jl interface for Trixi.jl
+module TrixiDiffEqBaseExt
+
+using Trixi: AbstractTimeIntegrator
+using DiffEqBase: DiffEqBase
+
+DiffEqBase.get_tstops(integrator::AbstractTimeIntegrator) = integrator.opts.tstops
+DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator) = get_tstops(integrator).valtree
+DiffEqBase.get_tstops_max(integrator::AbstractTimeIntegrator) = maximum(get_tstops_array(integrator))
+
+end # module TrixiDiffEqBaseExt
diff --git a/src/time_integration/methods_2N.jl b/src/time_integration/methods_2N.jl
index 71343b246fa..514b0bcfb99 100644
--- a/src/time_integration/methods_2N.jl
+++ b/src/time_integration/methods_2N.jl
@@ -14,7 +14,7 @@ abstract type SimpleAlgorithm2N end
 The following structures and methods provide a minimal implementation of
 the low-storage explicit Runge-Kutta method of
 
-- Carpenter, Kennedy (1994) 
+- Carpenter, Kennedy (1994)
   Fourth-order 2N-storage Runge-Kutta schemes (Solution 3)
   URL: https://ntrs.nasa.gov/citations/19940028444
   File: https://ntrs.nasa.gov/api/citations/19940028444/downloads/19940028444.pdf
@@ -53,7 +53,7 @@ end
 The following structures and methods provide a minimal implementation of
 the low-storage explicit Runge-Kutta method of
 
-- Carpenter, Kennedy (1994) 
+- Carpenter, Kennedy (1994)
   Third-order 2N-storage Runge-Kutta schemes with error control
   URL: https://ntrs.nasa.gov/citations/19940028444
   File: https://ntrs.nasa.gov/api/citations/19940028444/downloads/19940028444.pdf
@@ -91,7 +91,7 @@ end
 # https://diffeq.sciml.ai/v6.8/basics/integrator/#Handing-Integrators-1
 # which are used in Trixi.jl.
 mutable struct SimpleIntegrator2N{RealT <: Real, uType, Params, Sol, F, Alg,
-                                  SimpleIntegrator2NOptions}
+                                  SimpleIntegrator2NOptions} <: AbstractTimeIntegrator
     u::uType #
     du::uType
     u_tmp::uType
@@ -232,7 +232,7 @@ function set_proposed_dt!(integrator::SimpleIntegrator2N, dt)
     integrator.dt = dt
 end
 
-# Required e.g. for `glm_speed_callback` 
+# Required e.g. for `glm_speed_callback`
 function get_proposed_dt(integrator::SimpleIntegrator2N)
     return integrator.dt
 end
diff --git a/src/time_integration/methods_3Sstar.jl b/src/time_integration/methods_3Sstar.jl
index 51501c6189e..dd02b40f40a 100644
--- a/src/time_integration/methods_3Sstar.jl
+++ b/src/time_integration/methods_3Sstar.jl
@@ -145,7 +145,7 @@ function SimpleIntegrator3SstarOptions(callback, tspan; maxiters = typemax(Int),
 end
 
 mutable struct SimpleIntegrator3Sstar{RealT <: Real, uType, Params, Sol, F, Alg,
-                                      SimpleIntegrator3SstarOptions}
+                                      SimpleIntegrator3SstarOptions} <: AbstractTimeIntegrator
     u::uType #
     du::uType
     u_tmp1::uType
@@ -298,7 +298,7 @@ function set_proposed_dt!(integrator::SimpleIntegrator3Sstar, dt)
     integrator.dt = dt
 end
 
-# Required e.g. for `glm_speed_callback` 
+# Required e.g. for `glm_speed_callback`
 function get_proposed_dt(integrator::SimpleIntegrator3Sstar)
     return integrator.dt
 end
diff --git a/src/time_integration/methods_SSP.jl b/src/time_integration/methods_SSP.jl
index 33d1f164138..ee01ae58589 100644
--- a/src/time_integration/methods_SSP.jl
+++ b/src/time_integration/methods_SSP.jl
@@ -78,7 +78,7 @@ end
 # https://diffeq.sciml.ai/v6.8/basics/integrator/#Handing-Integrators-1
 # which are used in Trixi.
 mutable struct SimpleIntegratorSSP{RealT <: Real, uType, Params, Sol, F, Alg,
-                                   SimpleIntegratorSSPOptions}
+                                   SimpleIntegratorSSPOptions} <: AbstractTimeIntegrator
     u::uType
     du::uType
     r0::uType
diff --git a/src/time_integration/paired_explicit_runge_kutta/paired_explicit_runge_kutta.jl b/src/time_integration/paired_explicit_runge_kutta/paired_explicit_runge_kutta.jl
index 87f067fc39d..ddf6827c010 100644
--- a/src/time_integration/paired_explicit_runge_kutta/paired_explicit_runge_kutta.jl
+++ b/src/time_integration/paired_explicit_runge_kutta/paired_explicit_runge_kutta.jl
@@ -8,7 +8,7 @@
 # Define all of the functions necessary for polynomial optimizations
 include("polynomial_optimizer.jl")
 
-# Abstract base type for both single/standalone and multi-level 
+# Abstract base type for both single/standalone and multi-level
 # PERK (Paired-Explicit Runge-Kutta) time integration schemes
 abstract type AbstractPairedExplicitRK end
 # Abstract base type for single/standalone PERK time integration schemes
@@ -36,7 +36,7 @@ function PairedExplicitRKOptions(callback, tspan; maxiters = typemax(Int), kwarg
                                                                        tstops_internal)
 end
 
-abstract type AbstractPairedExplicitRKIntegrator end
+abstract type AbstractPairedExplicitRKIntegrator <: AbstractTimeIntegrator end
 abstract type AbstractPairedExplicitRKSingleIntegrator <:
               AbstractPairedExplicitRKIntegrator end
 
@@ -176,7 +176,7 @@ end
 
 """
     modify_dt_for_tstops!(integrator::PairedExplicitRK)
- 
+
 Modify the time-step size to match the time stops specified in integrator.opts.tstops.
 To avoid adding OrdinaryDiffEq to Trixi's dependencies, this routine is a copy of
 https://github.com/SciML/OrdinaryDiffEq.jl/blob/d76335281c540ee5a6d1bd8bb634713e004f62ee/src/integrators/integrator_utils.jl#L38-L54
diff --git a/src/time_integration/time_integration.jl b/src/time_integration/time_integration.jl
index d19a1fcc37c..81145a090e1 100644
--- a/src/time_integration/time_integration.jl
+++ b/src/time_integration/time_integration.jl
@@ -13,6 +13,9 @@ struct TimeIntegratorSolution{tType, uType, P}
     prob::P
 end
 
+# Abstract supertype of Trixi.jl\s own time integrators for dispatch
+abstract type AbstractTimeIntegrator end
+
 include("methods_2N.jl")
 include("methods_3Sstar.jl")
 include("methods_SSP.jl")

From a76946a68739bd5223734389424ae4834fb9c79c Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:12:21 +0100
Subject: [PATCH 14/39] ignore several run folders

---
 .gitignore | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/.gitignore b/.gitignore
index b4f1cf6bb47..4c4206151e1 100644
--- a/.gitignore
+++ b/.gitignore
@@ -28,7 +28,7 @@ coverage_report/
 
 .DS_Store
 
-run
-run/*
+run*/
+run*/*
 
 LocalPreferences.toml

From d79b2d39d1f9a001900b396c22e95a66da3b9772 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:13:14 +0100
Subject: [PATCH 15/39] sort alphabetically

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

diff --git a/Project.toml b/Project.toml
index c1c129d7985..9c84aac7a7d 100644
--- a/Project.toml
+++ b/Project.toml
@@ -58,8 +58,8 @@ Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 NLsolve = "2774e3e8-f4cf-5e23-947b-6d7e65073b56"
 
 [extensions]
-TrixiDiffEqBaseExt = "DiffEqBase"
 TrixiConvexECOSExt = ["Convex", "ECOS"]
+TrixiDiffEqBaseExt = "DiffEqBase"
 TrixiMakieExt = "Makie"
 TrixiNLsolveExt = "NLsolve"
 

From a9a296444354d2aac347af660b00712077cc48c8 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:13:41 +0100
Subject: [PATCH 16/39] format

---
 ext/TrixiDiffEqBaseExt.jl              | 8 ++++++--
 src/time_integration/methods_3Sstar.jl | 3 ++-
 2 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/ext/TrixiDiffEqBaseExt.jl b/ext/TrixiDiffEqBaseExt.jl
index 4737dc978b2..556b4ca56b5 100644
--- a/ext/TrixiDiffEqBaseExt.jl
+++ b/ext/TrixiDiffEqBaseExt.jl
@@ -5,7 +5,11 @@ using Trixi: AbstractTimeIntegrator
 using DiffEqBase: DiffEqBase
 
 DiffEqBase.get_tstops(integrator::AbstractTimeIntegrator) = integrator.opts.tstops
-DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator) = get_tstops(integrator).valtree
-DiffEqBase.get_tstops_max(integrator::AbstractTimeIntegrator) = maximum(get_tstops_array(integrator))
+function DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator)
+    get_tstops(integrator).valtree
+end
+function DiffEqBase.get_tstops_max(integrator::AbstractTimeIntegrator)
+    maximum(get_tstops_array(integrator))
+end
 
 end # module TrixiDiffEqBaseExt
diff --git a/src/time_integration/methods_3Sstar.jl b/src/time_integration/methods_3Sstar.jl
index dd02b40f40a..30889d2aa17 100644
--- a/src/time_integration/methods_3Sstar.jl
+++ b/src/time_integration/methods_3Sstar.jl
@@ -145,7 +145,8 @@ function SimpleIntegrator3SstarOptions(callback, tspan; maxiters = typemax(Int),
 end
 
 mutable struct SimpleIntegrator3Sstar{RealT <: Real, uType, Params, Sol, F, Alg,
-                                      SimpleIntegrator3SstarOptions} <: AbstractTimeIntegrator
+                                      SimpleIntegrator3SstarOptions} <:
+               AbstractTimeIntegrator
     u::uType #
     du::uType
     u_tmp1::uType

From 17f5abe69743cfa7bf93f21bbbf53fcc2fdfb1cd Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:15:25 +0100
Subject: [PATCH 17/39] import fix

---
 ext/TrixiDiffEqBaseExt.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/ext/TrixiDiffEqBaseExt.jl b/ext/TrixiDiffEqBaseExt.jl
index 556b4ca56b5..352ace13810 100644
--- a/ext/TrixiDiffEqBaseExt.jl
+++ b/ext/TrixiDiffEqBaseExt.jl
@@ -2,7 +2,7 @@
 module TrixiDiffEqBaseExt
 
 using Trixi: AbstractTimeIntegrator
-using DiffEqBase: DiffEqBase
+using DiffEqBase: DiffEqBase, get_tstops, get_tstops_array, get_tstops_max
 
 DiffEqBase.get_tstops(integrator::AbstractTimeIntegrator) = integrator.opts.tstops
 function DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator)

From d74506f4be071699014cfa3c566c4772f28d8aa9 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:16:10 +0100
Subject: [PATCH 18/39] allow v3 of DiffEqCallbacks

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

diff --git a/Project.toml b/Project.toml
index 9c84aac7a7d..4e3b1870ae7 100644
--- a/Project.toml
+++ b/Project.toml
@@ -71,7 +71,7 @@ Convex = "0.16"
 DataStructures = "0.18.15"
 DelimitedFiles = "1"
 DiffEqBase = "6.154"
-DiffEqCallbacks = "2.35, 4"
+DiffEqCallbacks = "2.35, 3, 4"
 Downloads = "1.6"
 ECOS = "1.1.2"
 EllipsisNotation = "1.0"

From 8805345eb3a309048fcba58a907fc941094fabfe Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:19:08 +0100
Subject: [PATCH 19/39] require Static.jl v1 for DiffEqBase.jl v6.154 (required
 for new DiffEqCallbacks stuff)

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

diff --git a/Project.toml b/Project.toml
index 4e3b1870ae7..8a5dea5ffca 100644
--- a/Project.toml
+++ b/Project.toml
@@ -101,7 +101,7 @@ SimpleUnPack = "1.1"
 SparseArrays = "1"
 StableRNGs = "1.0.2"
 StartUpDG = "1.1.5"
-Static = "0.8.7, 1"
+Static = "1"
 StaticArrayInterface = "1.4"
 StaticArrays = "1.9"
 StrideArrays = "0.1.26"

From dae8491c04796b7afe68e7e7f5917865e02d4804 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 12:30:59 +0100
Subject: [PATCH 20/39] require StaticArrayInterface 1.5.1 for Static.jl v1

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

diff --git a/Project.toml b/Project.toml
index 8a5dea5ffca..670da067096 100644
--- a/Project.toml
+++ b/Project.toml
@@ -102,7 +102,7 @@ SparseArrays = "1"
 StableRNGs = "1.0.2"
 StartUpDG = "1.1.5"
 Static = "1"
-StaticArrayInterface = "1.4"
+StaticArrayInterface = "1.5.1"
 StaticArrays = "1.9"
 StrideArrays = "0.1.26"
 StructArrays = "0.6.18"

From 2c11e003fb3e38d59483e20fa7096dd8d1efe25e Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 12:44:25 +0100
Subject: [PATCH 21/39] fix Aqua tests

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

diff --git a/ext/TrixiDiffEqBaseExt.jl b/ext/TrixiDiffEqBaseExt.jl
index 352ace13810..b0b694b735d 100644
--- a/ext/TrixiDiffEqBaseExt.jl
+++ b/ext/TrixiDiffEqBaseExt.jl
@@ -2,7 +2,7 @@
 module TrixiDiffEqBaseExt
 
 using Trixi: AbstractTimeIntegrator
-using DiffEqBase: DiffEqBase, get_tstops, get_tstops_array, get_tstops_max
+using DiffEqBase: DiffEqBase, get_tstops, get_tstops_array
 
 DiffEqBase.get_tstops(integrator::AbstractTimeIntegrator) = integrator.opts.tstops
 function DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator)
diff --git a/test/test_aqua.jl b/test/test_aqua.jl
index 175c4113f23..9b3f2d67903 100644
--- a/test/test_aqua.jl
+++ b/test/test_aqua.jl
@@ -15,7 +15,7 @@ include("test_trixi.jl")
                   piracies = (treat_as_own = [Trixi.StartUpDG.RefElemData,
                                   Trixi.StartUpDG.MeshData],),
                   # exception necessary because StableRNGs.jl is only used in an extension
-                  stale_deps = (ignore = [StableRNGs]))
+                  stale_deps = (ignore = [:StableRNGs],))
     @test isnothing(check_no_implicit_imports(Trixi,
                                               skip = (Core, Base, Trixi.P4est, Trixi.T8code,
                                                       Trixi.EllipsisNotation)))

From 599e1d43518e1e320e0a1cb13bd4c938beadf217 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:04:04 +0100
Subject: [PATCH 22/39] fix test values

---
 test/test_parabolic_1d.jl    |  8 ++++----
 test/test_tree_1d_fdsbp.jl   | 24 ++++++++++++------------
 test/test_tree_1d_hypdiff.jl |  9 ++++-----
 test/test_unstructured_2d.jl | 31 +++++++++++++++++--------------
 4 files changed, 37 insertions(+), 35 deletions(-)

diff --git a/test/test_parabolic_1d.jl b/test/test_parabolic_1d.jl
index 72e3b19a9c7..714095a0b81 100644
--- a/test/test_parabolic_1d.jl
+++ b/test/test_parabolic_1d.jl
@@ -16,8 +16,8 @@ isdir(outdir) && rm(outdir, recursive = true)
     @test_trixi_include(joinpath(examples_dir(), "tree_1d_dgsem",
                                  "elixir_advection_diffusion.jl"),
                         initial_refinement_level=4, tspan=(0.0, 0.4), polydeg=3,
-                        l2=[8.389498188525518e-06],
-                        linf=[2.847421658558336e-05])
+                        l2=[8.40483031802723e-6],
+                        linf=[2.8990878868540015e-5])
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
     let
@@ -64,8 +64,8 @@ end
                 abstol = time_abs_tol, reltol = time_int_tol,
                 save_everystep = false, callback = callbacks)
     l2_error, linf_error = analysis_callback(sol)
-    @test l2_error ≈ [6.4878111416468355e-6]
-    @test linf_error ≈ [3.258075790424364e-5]
+    @test l2_error ≈ [6.487940740394583e-6]
+    @test linf_error ≈ [3.262867898701227e-5]
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
     let
diff --git a/test/test_tree_1d_fdsbp.jl b/test/test_tree_1d_fdsbp.jl
index 71e77eeb389..5034ab2ca4a 100644
--- a/test/test_tree_1d_fdsbp.jl
+++ b/test/test_tree_1d_fdsbp.jl
@@ -116,14 +116,14 @@ end
     @trixi_testset "elixir_euler_convergence.jl with splitting_vanleer_haenel" begin
         @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_euler_convergence.jl"),
                             l2=[
-                                3.413790589105506e-6,
-                                4.243957977156001e-6,
-                                8.667369423676437e-6
+                                3.4137906030996366e-6,
+                                4.24395804622208e-6,
+                                8.667369559486434e-6
                             ],
                             linf=[
-                                1.4228079689537765e-5,
-                                1.3249887941046978e-5,
-                                3.201552933251861e-5
+                                1.4228079725286946e-5,
+                                1.324988815953887e-5,
+                                3.20155297650615e-5
                             ],
                             tspan=(0.0, 0.5),
                             flux_splitting=splitting_vanleer_haenel)
@@ -141,14 +141,14 @@ end
     @trixi_testset "elixir_euler_convergence.jl with VolumeIntegralStrongForm" begin
         @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_euler_convergence.jl"),
                             l2=[
-                                8.6126767518378e-6,
-                                7.670897071480729e-6,
-                                1.4972772284191368e-5
+                                8.612676636826464e-6,
+                                7.670896994006107e-6,
+                                1.4972772137651304e-5
                             ],
                             linf=[
-                                6.707982777909294e-5,
-                                3.487256699541419e-5,
-                                0.00010170331350556339
+                                6.707982749043495e-5,
+                                3.48725672254524e-5,
+                                0.00010170331503767116
                             ],
                             tspan=(0.0, 0.5),
                             solver=DG(D_upw.central, nothing, SurfaceIntegralStrongForm(),
diff --git a/test/test_tree_1d_hypdiff.jl b/test/test_tree_1d_hypdiff.jl
index cd570c16708..2f253d30615 100644
--- a/test/test_tree_1d_hypdiff.jl
+++ b/test/test_tree_1d_hypdiff.jl
@@ -12,9 +12,8 @@ EXAMPLES_DIR = pkgdir(Trixi, "examples", "tree_1d_dgsem")
 
 @trixi_testset "elixir_hypdiff_nonperiodic.jl" begin
     @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_hypdiff_nonperiodic.jl"),
-                        l2=[1.3655114954641076e-7, 1.0200345025539218e-6],
-                        linf=[7.173286515893551e-7, 4.507116363683394e-6],
-                        atol=2.5e-13)
+                        l2=[1.3655114953278825e-7, 1.0200345026471077e-6],
+                        linf=[7.173285075379177e-7, 4.507116828644797e-6])
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
     let
@@ -37,8 +36,8 @@ end
         t = sol.t[end]
         u_ode = sol.u[end]
         du_ode = similar(u_ode)
-        # Larger values for allowed allocations due to usage of custom 
-        # integrator which are not *recorded* for the methods from 
+        # Larger values for allowed allocations due to usage of custom
+        # integrator which are not *recorded* for the methods from
         # OrdinaryDiffEq.jl
         # Corresponding issue: https://github.com/trixi-framework/Trixi.jl/issues/1877
         @test (@allocated Trixi.rhs!(du_ode, u_ode, semi, t)) < 10000
diff --git a/test/test_unstructured_2d.jl b/test/test_unstructured_2d.jl
index cec7152f4fc..9653726f57d 100644
--- a/test/test_unstructured_2d.jl
+++ b/test/test_unstructured_2d.jl
@@ -17,12 +17,12 @@ isdir(outdir) && rm(outdir, recursive = true)
 @trixi_testset "elixir_euler_periodic.jl" begin
     @test_trixi_include(joinpath(EXAMPLES_DIR, "elixir_euler_periodic.jl"),
                         l2=[
-                            0.0001099216141882387, 0.0001303795774982892,
-                            0.00013037957749794242, 0.0002993727892598759
+                            0.00010992161458946449, 0.00013037957831794187,
+                            0.0001303795783182231, 0.00029937279106433015
                         ],
                         linf=[
-                            0.006407280810928562, 0.009836067015418948,
-                            0.009836067015398076, 0.021903519038095176
+                            0.006407280909098478, 0.009836067162309448,
+                            0.009836067162292128, 0.021903519372712843
                         ])
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
@@ -692,17 +692,20 @@ end
 @trixi_testset "FDSBP (upwind): elixir_euler_source_terms_upwind.jl with LF splitting" begin
     @test_trixi_include(joinpath(pkgdir(Trixi, "examples", "unstructured_2d_fdsbp"),
                                  "elixir_euler_source_terms_upwind.jl"),
-                        l2=[3.8300267071890586e-5,
-                            5.295846741663533e-5,
-                            5.295846741663526e-5,
-                            0.00017564759295593478],
-                        linf=[0.00018810716496542312,
-                            0.0003794187430412599,
-                            0.0003794187430412599,
-                            0.0009632958510650269],
+                        l2=[
+                            3.8300274213823844e-5,
+                            5.295847308063744e-5,
+                            5.295847308066259e-5,
+                            0.00017564760044077823
+                        ],
+                        linf=[
+                            0.0001881071653406785,
+                            0.00037941874324110003,
+                            0.0003794187432419882,
+                            0.0009632958467822306
+                        ],
                         tspan=(0.0, 0.025),
-                        flux_splitting=splitting_lax_friedrichs,
-                        atol=1.0e-10)
+                        flux_splitting=splitting_lax_friedrichs)
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
     let

From 3760a8ef740b2100a7ae7e0e0c16cc4977baf463 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:09:28 +0100
Subject: [PATCH 23/39] fix restart_file

---
 examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl b/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
index b16963762fd..a4c495e7f28 100644
--- a/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
+++ b/examples/tree_1d_dgsem/elixir_advection_diffusion_restart.jl
@@ -10,7 +10,7 @@ trixi_include(@__MODULE__, joinpath(@__DIR__, elixir_file))
 ###############################################################################
 # initialize the ODE
 
-restart_file = "restart_000000018.h5"
+restart_file = "restart_000000012.h5"
 restart_filename = joinpath("out", restart_file)
 tspan = (load_time(restart_filename), 2.0)
 

From 19e1911915f464ac25559e5c046347ffbe47742e Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 13:12:50 +0100
Subject: [PATCH 24/39] require Octavian.jl v0.3.28 for Static.jl

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

diff --git a/Project.toml b/Project.toml
index 670da067096..39070e75367 100644
--- a/Project.toml
+++ b/Project.toml
@@ -85,7 +85,7 @@ MPI = "0.20.6"
 Makie = "0.21, 0.22"
 MuladdMacro = "0.2.2"
 NLsolve = "4.5.1"
-Octavian = "0.3.21"
+Octavian = "0.3.28"
 OffsetArrays = "1.13"
 P4est = "0.4.12"
 Polyester = "0.7.10"

From f407ec1d6b33c6a6c205109db161fbac8b4ea05b Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:17:22 +0100
Subject: [PATCH 25/39] require LoopVectorization.jl v0.12.171 for Static.jl

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

diff --git a/Project.toml b/Project.toml
index 39070e75367..01cd969b70e 100644
--- a/Project.toml
+++ b/Project.toml
@@ -80,7 +80,7 @@ ForwardDiff = "0.10.36"
 HDF5 = "0.16.10, 0.17"
 LinearAlgebra = "1"
 LinearMaps = "2.7, 3.0"
-LoopVectorization = "0.12.151"
+LoopVectorization = "0.12.171"
 MPI = "0.20.6"
 Makie = "0.21, 0.22"
 MuladdMacro = "0.2.2"

From da9648880fd8e7bb98c375a11227024cdd14fafc Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:19:21 +0100
Subject: [PATCH 26/39] require StrideArrays.jl v0.1.29 for Static.jl

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

diff --git a/Project.toml b/Project.toml
index 01cd969b70e..17c4a0579ec 100644
--- a/Project.toml
+++ b/Project.toml
@@ -104,7 +104,7 @@ StartUpDG = "1.1.5"
 Static = "1"
 StaticArrayInterface = "1.5.1"
 StaticArrays = "1.9"
-StrideArrays = "0.1.26"
+StrideArrays = "0.1.29"
 StructArrays = "0.6.18"
 SummationByPartsOperators = "0.5.52"
 T8code = "0.7.4"

From d2f158778501ff30afecc8b0998c9559182e540c Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:21:04 +0100
Subject: [PATCH 27/39] require Polyester.jl v0.7.15 for Static.jl

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

diff --git a/Project.toml b/Project.toml
index 17c4a0579ec..3276485d4ae 100644
--- a/Project.toml
+++ b/Project.toml
@@ -88,7 +88,7 @@ NLsolve = "4.5.1"
 Octavian = "0.3.28"
 OffsetArrays = "1.13"
 P4est = "0.4.12"
-Polyester = "0.7.10"
+Polyester = "0.7.15"
 PrecompileTools = "1.2"
 Preferences = "1.4"
 Printf = "1"

From 1f08a5cc7fb851d4f40944a2ec24642686dbb80c Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 13:20:37 +0100
Subject: [PATCH 28/39] fix typo

---
 src/time_integration/time_integration.jl | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/src/time_integration/time_integration.jl b/src/time_integration/time_integration.jl
index 81145a090e1..c810c00d8ce 100644
--- a/src/time_integration/time_integration.jl
+++ b/src/time_integration/time_integration.jl
@@ -13,7 +13,7 @@ struct TimeIntegratorSolution{tType, uType, P}
     prob::P
 end
 
-# Abstract supertype of Trixi.jl\s own time integrators for dispatch
+# Abstract supertype of Trixi.jl's own time integrators for dispatch
 abstract type AbstractTimeIntegrator end
 
 include("methods_2N.jl")

From 7dba3cd3f6ec330b336ebadde603429d69703633 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 13:30:45 +0100
Subject: [PATCH 29/39] require OrdinaryDiffEq.jl v6.88 for FastBroadcast.jl
 version required by Static.jl v1

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

diff --git a/test/Project.toml b/test/Project.toml
index f10379628d7..095ae3f5401 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -36,7 +36,7 @@ ForwardDiff = "0.10.36"
 LinearAlgebra = "1"
 MPI = "0.20.6"
 NLsolve = "4.5.1"
-OrdinaryDiffEq = "6.75"
+OrdinaryDiffEq = "6.88"
 Plots = "1.26"
 Printf = "1"
 Quadmath = "0.5.10"

From 4c756670acf0a2f52e19a77d66618f400c13b4ac Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:37:03 +0100
Subject: [PATCH 30/39] require Polyester.jl v0.7.16 for OrdinaryDiffEqPRK.jl

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

diff --git a/Project.toml b/Project.toml
index 3276485d4ae..ae9bb56718f 100644
--- a/Project.toml
+++ b/Project.toml
@@ -88,7 +88,7 @@ NLsolve = "4.5.1"
 Octavian = "0.3.28"
 OffsetArrays = "1.13"
 P4est = "0.4.12"
-Polyester = "0.7.15"
+Polyester = "0.7.16"
 PrecompileTools = "1.2"
 Preferences = "1.4"
 Printf = "1"

From b844ee586cf2da62cd2aae8f7779e594d2f4b593 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:39:16 +0100
Subject: [PATCH 31/39] require MuladdMacro v0.2.4 for OrdinaryDiffEqPRK.jl

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

diff --git a/Project.toml b/Project.toml
index ae9bb56718f..708d6e135d3 100644
--- a/Project.toml
+++ b/Project.toml
@@ -83,7 +83,7 @@ LinearMaps = "2.7, 3.0"
 LoopVectorization = "0.12.171"
 MPI = "0.20.6"
 Makie = "0.21, 0.22"
-MuladdMacro = "0.2.2"
+MuladdMacro = "0.2.4"
 NLsolve = "4.5.1"
 Octavian = "0.3.28"
 OffsetArrays = "1.13"

From 832dd8dd560dedbac8a157f40d77b0bca18ec223 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:43:05 +0100
Subject: [PATCH 32/39] require Static.jl v1.1.1 for
 OrdinaryDiffEqHighOrderRK.jl

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

diff --git a/Project.toml b/Project.toml
index 708d6e135d3..4600d26a9b4 100644
--- a/Project.toml
+++ b/Project.toml
@@ -101,7 +101,7 @@ SimpleUnPack = "1.1"
 SparseArrays = "1"
 StableRNGs = "1.0.2"
 StartUpDG = "1.1.5"
-Static = "1"
+Static = "1.1.1"
 StaticArrayInterface = "1.5.1"
 StaticArrays = "1.9"
 StrideArrays = "0.1.29"

From 2fa1327aaa9a5e5772edb0fde92224045301a8b7 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 13:45:30 +0100
Subject: [PATCH 33/39] require ADTypes.jl v1.7.1 for
 OrdinaryDiffEqNonlinearSolve.jl

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

diff --git a/test/Project.toml b/test/Project.toml
index 095ae3f5401..1612dde3d26 100644
--- a/test/Project.toml
+++ b/test/Project.toml
@@ -22,7 +22,7 @@ StableRNGs = "860ef19b-820b-49d6-a774-d7a799459cd3"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
 
 [compat]
-ADTypes = "1.1"
+ADTypes = "1.7.1"
 Aqua = "0.8"
 CairoMakie = "0.12, 0.13"
 Convex = "0.16"

From eb3d7789ff58b41fe8063f9ab1b6f6322d5d2839 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 14:23:31 +0100
Subject: [PATCH 34/39] fix documentation about PERK methods

---
 docs/src/time_integration.md | 42 ++++++++++++++++++------------------
 1 file changed, 21 insertions(+), 21 deletions(-)

diff --git a/docs/src/time_integration.md b/docs/src/time_integration.md
index 3cdb7fa75ae..504db03b3c3 100644
--- a/docs/src/time_integration.md
+++ b/docs/src/time_integration.md
@@ -13,7 +13,7 @@ Some common options for `solve` from [OrdinaryDiffEq.jl](https://github.com/SciM
 are the following. Further documentation can be found in the
 [SciML docs](https://diffeq.sciml.ai/v6.8/basics/common_solver_opts/).
 - If you use a fixed time step method like `CarpenterKennedy2N54`, you need to pass
-  a time step as `dt=...`. If you use a [`StepsizeCallback`](@ref), the value passed 
+  a time step as `dt=...`. If you use a [`StepsizeCallback`](@ref), the value passed
   as `dt=...` is irrelevant since it will be overwritten by the [`StepsizeCallback`](@ref).
   If you want to use an adaptive time step method such as `SSPRK43` or `RDPK3SpFSAL49`
   and still want to use CFL-based step size control via the [`StepsizeCallback`](@ref),
@@ -25,12 +25,12 @@ are the following. Further documentation can be found in the
 - SSP methods and many low-storage methods from OrdinaryDiffEq.jl support
   `stage_limiter!`s and `step_limiter!`s, e.g., [`PositivityPreservingLimiterZhangShu`](@ref) and [`EntropyBoundedLimiter`](@ref)
   from Trixi.jl.
-- If you start Julia with multiple threads and want to use them also in the time 
+- If you start Julia with multiple threads and want to use them also in the time
   integration method from OrdinaryDiffEq.jl, you need to pass the keyword argument
-  `thread=OrdinaryDiffEq.True()` to the algorithm, e.g., 
-  `RDPK3SpFSAL49(thread=OrdinaryDiffEq.True())` or 
+  `thread=OrdinaryDiffEq.True()` to the algorithm, e.g.,
+  `RDPK3SpFSAL49(thread=OrdinaryDiffEq.True())` or
   `CarpenterKennedy2N54(thread=OrdinaryDiffEq.True(), williamson_condition=false)`.
-  For more information on using thread-based parallelism in Trixi.jl, please refer to 
+  For more information on using thread-based parallelism in Trixi.jl, please refer to
   [Shared-memory parallelization with threads](@ref).
 - If you use error-based step size control (see also the section on
   [error-based adaptive step sizes](@ref adaptive_step_sizes)) together with MPI, you need to
@@ -50,7 +50,7 @@ are the following. Further documentation can be found in the
 ### Stabilized Explicit Runge-Kutta Methods
 
 Optimized explicit schemes aim to maximize the timestep $\Delta t$ for a given simulation setup.
-Formally, this boils down to an optimization problem of the form 
+Formally, this boils down to an optimization problem of the form
 ```math
 \underset{P_{p;S} \, \in \, \mathcal{P}_{p;S}}{\max} \Delta t \text{ such that } \big \vert P_{p;S}(\Delta t \lambda_m) \big \vert \leq 1, \quad  m = 1 , \dots , M \tag{1}
 ```
@@ -79,12 +79,12 @@ Nevertheless, due to their optimized stability properties and low-storage nature
 
 #### Tutorial: Using `PairedExplicitRK2`
 
-In this tutorial, we will demonstrate how you can use the second-order PERK time integrator. You need the packages `Convex.jl` and `ECOS.jl`, so be sure they are added to your environment.
+In this tutorial, we will demonstrate how you can use the second-order PERK time integrator. You need the packages `Convex.jl`, `ECOS.jl`, and `NLsolve.jl`, so be sure they are added to your environment.
 
 First, you need to load the necessary packages:
 
 ```@example PERK-example-1
-using Convex, ECOS
+using Convex, ECOS, NLsolve
 using OrdinaryDiffEq
 using Trixi
 ```
@@ -96,7 +96,7 @@ Then, define the ODE problem and the semidiscretization setup. For this example,
 cells_per_dimension = 100
 coordinates_min = 0.0
 coordinates_max = 1.0
-mesh = StructuredMesh(cells_per_dimension, 
+mesh = StructuredMesh(cells_per_dimension,
                       coordinates_min, coordinates_max)
 
 # Define the equation and initial condition
@@ -109,8 +109,8 @@ initial_condition = initial_condition_convergence_test
 solver = DGSEM(polydeg = 3, surface_flux = flux_lax_friedrichs)
 
 # Define the semidiscretization
-semi = SemidiscretizationHyperbolic(mesh, 
-                                    equations, initial_condition, 
+semi = SemidiscretizationHyperbolic(mesh,
+                                    equations, initial_condition,
                                     solver)
 ```
 
@@ -125,14 +125,14 @@ analysis_callback = AnalysisCallback(semi, interval = 200)
 stepsize_callback = StepsizeCallback(cfl = 2.5)
 
 # Create a CallbackSet to collect all callbacks
-callbacks = CallbackSet(summary_callback, 
-                        alive_callback, 
-                        analysis_callback, 
+callbacks = CallbackSet(summary_callback,
+                        alive_callback,
+                        analysis_callback,
                         stepsize_callback)
 ```
 
-Now, we define the ODE problem by specifying the time span over which the ODE will be solved. 
-The `tspan` parameter is a tuple `(t_start, t_end)` that defines the start and end times for the simulation. 
+Now, we define the ODE problem by specifying the time span over which the ODE will be solved.
+The `tspan` parameter is a tuple `(t_start, t_end)` that defines the start and end times for the simulation.
 The `semidiscretize` function is used to create the ODE problem from the simulation setup.
 
 ```@example PERK-example-1
@@ -145,10 +145,10 @@ ode = semidiscretize(semi, tspan)
 
 Next, we will construct the time integrator. In order to do this, you need the following components:
 
-  - Number of stages: The number of stages $S$ in the Runge-Kutta method. 
+  - Number of stages: The number of stages $S$ in the Runge-Kutta method.
   In this example, we use `6` stages.
-  - Time span (`tspan`): A tuple `(t_start, t_end)` that defines the time span over which the ODE will be solved. 
-  This defines the bounds for the bisection routine for the optimal timestep $\Delta t$ used in calculating the polynomial coefficients at optimization stage. 
+  - Time span (`tspan`): A tuple `(t_start, t_end)` that defines the time span over which the ODE will be solved.
+  This defines the bounds for the bisection routine for the optimal timestep $\Delta t$ used in calculating the polynomial coefficients at optimization stage.
   This variable is already defined in step 5.
   - Semidiscretization (`semi`): The semidiscretization setup that includes the mesh, equations, initial condition, and solver. In this example, this variable is already defined in step 3.
   In the background, we compute from `semi` the Jacobian $J$ evaluated at the initial condition using [`jacobian_ad_forward`](https://trixi-framework.github.io/Trixi.jl/stable/reference-trixi/#Trixi.jacobian_ad_forward-Tuple{Trixi.AbstractSemidiscretization}).
@@ -182,9 +182,9 @@ There are two additional constructors for the `PairedExplicitRK2` method besides
 
 In the previous tutorial the CFL number was set manually to $2.5$.
 To avoid the manual trial-and-error process behind this, instantiations of `AbstractPairedExplicitRK` methods can automatically compute the stable CFL number for a given simulation setup using the [`Trixi.calculate_cfl`](@ref) function.
-When constructing the time integrator from a semidiscretization `semi`, 
+When constructing the time integrator from a semidiscretization `semi`,
 ```@example PERK-example-1
-# Construct third-order paired-explicit Runge-Kutta method with 8 stages for given simulation setup.                               
+# Construct third-order paired-explicit Runge-Kutta method with 8 stages for given simulation setup.
 ode_algorithm = Trixi.PairedExplicitRK3(8, tspan, semi)
 ```
 the maximum timestep `dt` is stored by the `ode_algorithm`.

From b48479d328612eb881f45833f2713ab57d1347e7 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 14:34:56 +0100
Subject: [PATCH 35/39] fix some more test values and tolerances

---
 test/test_parabolic_1d.jl    | 4 ++--
 test/test_unstructured_2d.jl | 3 ++-
 2 files changed, 4 insertions(+), 3 deletions(-)

diff --git a/test/test_parabolic_1d.jl b/test/test_parabolic_1d.jl
index 714095a0b81..ee645819fc0 100644
--- a/test/test_parabolic_1d.jl
+++ b/test/test_parabolic_1d.jl
@@ -31,8 +31,8 @@ end
 @trixi_testset "TreeMesh1D: elixir_advection_diffusion_restart.jl" begin
     @test_trixi_include(joinpath(examples_dir(), "tree_1d_dgsem",
                                  "elixir_advection_diffusion_restart.jl"),
-                        l2=[1.0671615777620987e-5],
-                        linf=[3.861509422325993e-5])
+                        l2=[1.0679933947301556e-5],
+                        linf=[3.910500545667439e-5])
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
     let
diff --git a/test/test_unstructured_2d.jl b/test/test_unstructured_2d.jl
index 9653726f57d..259eb39c545 100644
--- a/test/test_unstructured_2d.jl
+++ b/test/test_unstructured_2d.jl
@@ -705,7 +705,8 @@ end
                             0.0009632958467822306
                         ],
                         tspan=(0.0, 0.025),
-                        flux_splitting=splitting_lax_friedrichs)
+                        flux_splitting=splitting_lax_friedrichs,
+                        atol=2e-10)
     # Ensure that we do not have excessive memory allocations
     # (e.g., from type instabilities)
     let

From d0b6f1f5620523b54205855845d98ee274c2297f Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 14:34:02 +0100
Subject: [PATCH 36/39] remove extras that are not required anymore since Julia
 v1.9

---
 Project.toml | 6 ------
 1 file changed, 6 deletions(-)

diff --git a/Project.toml b/Project.toml
index 4600d26a9b4..154cb45a3a8 100644
--- a/Project.toml
+++ b/Project.toml
@@ -115,9 +115,3 @@ TriplotRecipes = "0.1"
 TrixiBase = "0.1.3"
 UUIDs = "1.6"
 julia = "1.10"
-
-[extras]
-Convex = "f65535da-76fb-5f13-bab9-19810c17039a"
-ECOS = "e2685f51-7e38-5353-a97d-a921fd2c8199"
-Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
-NLsolve = "2774e3e8-f4cf-5e23-947b-6d7e65073b56"

From dd81e82e989255c9fccdc7ffb26e3d8be08de2ef Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <mail@ranocha.de>
Date: Fri, 7 Feb 2025 14:49:23 +0100
Subject: [PATCH 37/39] make DiffEqBase a regular dep instead of a weakdep

Trixi.jl depends on DiffEqBase.jl already via DiffEqCallbacks.jl. Making DiffEqBase.jl
a regular dep instead of a weakdep fixes a cyclic dependency issue with extensions.
---
 Project.toml                             |  3 +--
 ext/TrixiDiffEqBaseExt.jl                | 15 ---------------
 src/Trixi.jl                             |  1 +
 src/time_integration/time_integration.jl | 12 ++++++++++++
 4 files changed, 14 insertions(+), 17 deletions(-)
 delete mode 100644 ext/TrixiDiffEqBaseExt.jl

diff --git a/Project.toml b/Project.toml
index 154cb45a3a8..4690cdd6908 100644
--- a/Project.toml
+++ b/Project.toml
@@ -9,6 +9,7 @@ CodeTracking = "da1fd8a2-8d9e-5ec2-8556-3022fb5608a2"
 ConstructionBase = "187b0558-2788-49d3-abe0-74a17ed4e7c9"
 DataStructures = "864edb3b-99cc-5e75-8d2d-829cb0a9cfe8"
 DelimitedFiles = "8bb1440f-4735-579b-a4ab-409b98df4dab"
+DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 DiffEqCallbacks = "459566f4-90b8-5000-8ac3-15dfb0a30def"
 Downloads = "f43a241f-c20a-4ad4-852c-f6b1247861c6"
 EllipsisNotation = "da5c29d0-fa7d-589e-88eb-ea29b0a81949"
@@ -52,14 +53,12 @@ UUIDs = "cf7118a7-6976-5b1a-9a39-7adc72f591a4"
 
 [weakdeps]
 Convex = "f65535da-76fb-5f13-bab9-19810c17039a"
-DiffEqBase = "2b5f629d-d688-5b77-993f-72d75c75574e"
 ECOS = "e2685f51-7e38-5353-a97d-a921fd2c8199"
 Makie = "ee78f7c6-11fb-53f2-987a-cfe4a2b5a57a"
 NLsolve = "2774e3e8-f4cf-5e23-947b-6d7e65073b56"
 
 [extensions]
 TrixiConvexECOSExt = ["Convex", "ECOS"]
-TrixiDiffEqBaseExt = "DiffEqBase"
 TrixiMakieExt = "Makie"
 TrixiNLsolveExt = "NLsolve"
 
diff --git a/ext/TrixiDiffEqBaseExt.jl b/ext/TrixiDiffEqBaseExt.jl
deleted file mode 100644
index b0b694b735d..00000000000
--- a/ext/TrixiDiffEqBaseExt.jl
+++ /dev/null
@@ -1,15 +0,0 @@
-# Package extension for DiffEqBase.jl interface for Trixi.jl
-module TrixiDiffEqBaseExt
-
-using Trixi: AbstractTimeIntegrator
-using DiffEqBase: DiffEqBase, get_tstops, get_tstops_array
-
-DiffEqBase.get_tstops(integrator::AbstractTimeIntegrator) = integrator.opts.tstops
-function DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator)
-    get_tstops(integrator).valtree
-end
-function DiffEqBase.get_tstops_max(integrator::AbstractTimeIntegrator)
-    maximum(get_tstops_array(integrator))
-end
-
-end # module TrixiDiffEqBaseExt
diff --git a/src/Trixi.jl b/src/Trixi.jl
index ffe759d0750..162954ef515 100644
--- a/src/Trixi.jl
+++ b/src/Trixi.jl
@@ -45,6 +45,7 @@ using DelimitedFiles: readdlm
 using Downloads: Downloads
 using CodeTracking: CodeTracking
 using ConstructionBase: ConstructionBase
+using DiffEqBase: DiffEqBase, get_tstops, get_tstops_array
 using DiffEqCallbacks: PeriodicCallback, PeriodicCallbackAffect
 @reexport using EllipsisNotation # ..
 using FillArrays: Ones, Zeros
diff --git a/src/time_integration/time_integration.jl b/src/time_integration/time_integration.jl
index c810c00d8ce..0d37292c42b 100644
--- a/src/time_integration/time_integration.jl
+++ b/src/time_integration/time_integration.jl
@@ -16,8 +16,20 @@ end
 # Abstract supertype of Trixi.jl's own time integrators for dispatch
 abstract type AbstractTimeIntegrator end
 
+# Interface required by DiffEqCallbacks.jl
+function DiffEqBase.get_tstops(integrator::AbstractTimeIntegrator)
+    return integrator.opts.tstops
+end
+function DiffEqBase.get_tstops_array(integrator::AbstractTimeIntegrator)
+    return get_tstops(integrator).valtree
+end
+function DiffEqBase.get_tstops_max(integrator::AbstractTimeIntegrator)
+    return maximum(get_tstops_array(integrator))
+end
+
 include("methods_2N.jl")
 include("methods_3Sstar.jl")
 include("methods_SSP.jl")
 include("paired_explicit_runge_kutta/paired_explicit_runge_kutta.jl")
+
 end # @muladd

From 624c93235b1f5c5782218bea697c3fad29f08019 Mon Sep 17 00:00:00 2001
From: Hendrik Ranocha <ranocha@users.noreply.github.com>
Date: Fri, 7 Feb 2025 14:53:17 +0100
Subject: [PATCH 38/39] format

Co-authored-by: github-actions[bot] <41898282+github-actions[bot]@users.noreply.github.com>
---
 src/time_integration/time_integration.jl | 1 -
 1 file changed, 1 deletion(-)

diff --git a/src/time_integration/time_integration.jl b/src/time_integration/time_integration.jl
index 0d37292c42b..609526da5aa 100644
--- a/src/time_integration/time_integration.jl
+++ b/src/time_integration/time_integration.jl
@@ -31,5 +31,4 @@ include("methods_2N.jl")
 include("methods_3Sstar.jl")
 include("methods_SSP.jl")
 include("paired_explicit_runge_kutta/paired_explicit_runge_kutta.jl")
-
 end # @muladd

From 4a682ffdf971a9c05095a6fd0025359be5ed13b7 Mon Sep 17 00:00:00 2001
From: Joshua Lampert <joshua.lampert@uni-hamburg.de>
Date: Fri, 7 Feb 2025 15:19:20 +0100
Subject: [PATCH 39/39] add NLsolve to docs/Project.toml

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

diff --git a/docs/Project.toml b/docs/Project.toml
index 5d63e239e0b..01bde4897e8 100644
--- a/docs/Project.toml
+++ b/docs/Project.toml
@@ -9,6 +9,7 @@ HOHQMesh = "e4f4c7b8-17cb-445a-93c5-f69190ed6c8c"
 LaTeXStrings = "b964fa9f-0449-5b57-a5c2-d3ea65f4040f"
 Literate = "98b081ad-f1c9-55d3-8b20-4c87d4299306"
 Measurements = "eff96d63-e80a-5855-80a2-b1b0885c5ab7"
+NLsolve = "2774e3e8-f4cf-5e23-947b-6d7e65073b56"
 OrdinaryDiffEq = "1dea7af3-3e70-54e6-95c3-0bf5283fa5ed"
 Plots = "91a5bcdd-55d7-5caf-9e0b-520d859cae80"
 Test = "8dfed614-e22c-5e08-85e1-65c5234f0b40"
@@ -26,6 +27,7 @@ HOHQMesh = "0.1, 0.2"
 LaTeXStrings = "1.2"
 Literate = "2.9"
 Measurements = "2.5"
+NLsolve = "4.5.1"
 OrdinaryDiffEq = "6.49.1"
 Plots = "1.9"
 Test = "1"