From 9d6cde2bdad4d21f0fd3df35557ea767278b9346 Mon Sep 17 00:00:00 2001
From: Jan Nikl <nikl1@llnl.gov>
Date: Thu, 22 Oct 2026 17:19:26 -0700
Subject: [PATCH 1/3] Undefined bool type for hypre.

---
 build-hypre/action.yml | 1 +
 1 file changed, 1 insertion(+)

diff --git a/build-hypre/action.yml b/build-hypre/action.yml
index 72fdc0b..9d5a6ab 100644
--- a/build-hypre/action.yml
+++ b/build-hypre/action.yml
@@ -95,6 +95,7 @@ runs:
         cd ${{ inputs.dir }};
         install_prefix="$(pwd)/install";
         cd src;
+        export CFLAGS="${CFLAGS} -Ubool"
         ./configure --prefix=${install_prefix} ${hypre_options} CC=mpicc CXX=mpic++ || {
           echo "Hypre configuration failed. Contents of 'config.log':"
           cat config.log

From b73da67daff5059876d4e97ca609efc1ca642931 Mon Sep 17 00:00:00 2001
From: Jan Nikl <nikl1@llnl.gov>
Date: Thu, 22 Oct 2026 18:16:36 -0700
Subject: [PATCH 2/3] Pinned version of C/C++ for hypre compilation.

---
 build-hypre/action.yml | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/build-hypre/action.yml b/build-hypre/action.yml
index 9d5a6ab..f552a89 100644
--- a/build-hypre/action.yml
+++ b/build-hypre/action.yml
@@ -95,7 +95,8 @@ runs:
         cd ${{ inputs.dir }};
         install_prefix="$(pwd)/install";
         cd src;
-        export CFLAGS="${CFLAGS} -Ubool"
+        export CFLAGS="${CFLAGS} -std=c17"
+        export CXXFLAGS="${CXXFLAGS} -std=c++17"
         ./configure --prefix=${install_prefix} ${hypre_options} CC=mpicc CXX=mpic++ || {
           echo "Hypre configuration failed. Contents of 'config.log':"
           cat config.log

From fbf6c802ea18c6337a15d1701e2c77e31ceb5486 Mon Sep 17 00:00:00 2001
From: Jan Nikl <nikl1@llnl.gov>
Date: Fri, 23 Oct 2026 10:11:25 -0700
Subject: [PATCH 3/3] Pinned also CMake C/C++standard to 17.

---
 build-hypre/action.yml | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/build-hypre/action.yml b/build-hypre/action.yml
index f552a89..b9e1b24 100644
--- a/build-hypre/action.yml
+++ b/build-hypre/action.yml
@@ -95,6 +95,8 @@ runs:
         cd ${{ inputs.dir }};
         install_prefix="$(pwd)/install";
         cd src;
+        # Pin the version of C/C++ standard to avoid problems with C23 native
+        # bool type definition
         export CFLAGS="${CFLAGS} -std=c17"
         export CXXFLAGS="${CXXFLAGS} -std=c++17"
         ./configure --prefix=${install_prefix} ${hypre_options} CC=mpicc CXX=mpic++ || {
@@ -143,6 +145,8 @@ runs:
         cmake -Hsrc -Bbuild \
           ${hypre_options} \
           -DCMAKE_BUILD_TYPE=Release \
+          -DCMAKE_C_STANDARD=17 \
+          -DCMAKE_CXX_STANDARD=17 \
           -DCMAKE_INSTALL_PREFIX=install
         cmake --build build --config Release --parallel ${ntasks}
         cmake --install build --config Release