From a37c249279b2588fc5a6fa5a813c6035b3ac08d5 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Wed, 1 Apr 2026 14:52:48 -0500
Subject: [PATCH 01/18] Add changes to collect core dumps

---
 ci/cuopt_coredumps.sh          | 71 ++++++++++++++++++++++++++++++++++
 ci/test_cpp.sh                 |  7 ++++
 ci/test_cpp_memcheck.sh        |  7 ++++
 ci/test_notebooks.sh           |  7 ++++
 ci/test_python.sh              |  7 ++++
 ci/test_self_hosted_service.sh |  7 ++++
 ci/test_skills_assets.sh       |  7 ++++
 ci/test_wheel_cuopt.sh         |  7 ++++
 ci/test_wheel_cuopt_server.sh  |  7 ++++
 9 files changed, 127 insertions(+)
 create mode 100644 ci/cuopt_coredumps.sh

diff --git a/ci/cuopt_coredumps.sh b/ci/cuopt_coredumps.sh
new file mode 100644
index 0000000000..650382174b
--- /dev/null
+++ b/ci/cuopt_coredumps.sh
@@ -0,0 +1,71 @@
+#!/usr/bin/env bash
+
+# SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-License-Identifier: Apache-2.0
+
+# Enable core dumps during CI test scripts and collect files into
+# ${RAPIDS_ARTIFACTS_DIR}/coredumps so rapids-upload-artifacts-dir uploads them (S3).
+#
+# Shells: source this file from repo ci/ scripts, then call cuopt_enable_coredumps
+# and trap cuopt_collect_coredumps on EXIT.
+
+cuopt_enable_coredumps() {
+  local ws base pattern
+  ws="${GITHUB_WORKSPACE:-${PWD}}"
+  base="${RAPIDS_ARTIFACTS_DIR:-${ws}/artifacts}"
+  export CUOPT_COREDUMP_DIR="${base}/coredumps"
+  mkdir -p "${CUOPT_COREDUMP_DIR}"
+
+  ulimit -c unlimited 2>/dev/null || true
+
+  if [[ -w /proc/sys/kernel/core_pattern ]]; then
+    echo "${CUOPT_COREDUMP_DIR}/core.%e.%p.%t" >/proc/sys/kernel/core_pattern 2>/dev/null || true
+  fi
+
+  pattern="$(cat /proc/sys/kernel/core_pattern 2>/dev/null || echo n/a)"
+  if declare -F rapids-logger &>/dev/null; then
+    rapids-logger "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit -c=$(ulimit -c) core_pattern=${pattern}"
+  else
+    echo "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit -c=$(ulimit -c) core_pattern=${pattern}"
+  fi
+}
+
+cuopt_collect_coredumps() {
+  local ws base dest n_before n_after f rel dest_name dest_path
+  ws="${GITHUB_WORKSPACE:-${PWD}}"
+  base="${RAPIDS_ARTIFACTS_DIR:-${ws}/artifacts}"
+  dest="${base}/coredumps"
+  mkdir -p "${dest}"
+
+  n_before="$(find "${dest}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
+
+  while IFS= read -r -d '' f; do
+    [[ -f "${f}" ]] || continue
+    case "${f}" in
+      "${dest}/"*) continue ;;
+    esac
+    rel="${f#"${ws}"/}"
+    if [[ "${rel}" == "${f}" ]]; then
+      rel="$(basename "${f}")"
+    fi
+    dest_name="${rel//\//_}"
+    dest_path="${dest}/${dest_name}"
+    if [[ -e "${dest_path}" ]]; then
+      dest_path="${dest}/${dest_name}.${RANDOM}"
+    fi
+    cp -a "${f}" "${dest_path}" 2>/dev/null || true
+  done < <(
+    find "${ws}" \
+      \( -path '*/.git/*' -o -path '*/opt/conda/*' -o -path '*/conda_pkgs/*' -o -path '*/artifacts/coredumps/*' \) -prune -o \
+      \( -name 'core' -o -name 'core.*' \) -type f -print0 2>/dev/null
+  )
+
+  n_after="$(find "${dest}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
+  if [[ "${n_after}" -gt "${n_before}" ]]; then
+    if declare -F rapids-logger &>/dev/null; then
+      rapids-logger "Wrote $((n_after - n_before)) core file(s) into ${dest} (${n_after} total)"
+    else
+      echo "cuOpt coredumps: ${n_after} file(s) in ${dest}"
+    fi
+  fi
+}
diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index 653c44133a..570f4816d9 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -5,6 +5,13 @@
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 . /opt/conda/etc/profile.d/conda.sh
 
 rapids-logger "Configuring conda strict channel priority"
diff --git a/ci/test_cpp_memcheck.sh b/ci/test_cpp_memcheck.sh
index bc4bce4cbc..48199eecef 100755
--- a/ci/test_cpp_memcheck.sh
+++ b/ci/test_cpp_memcheck.sh
@@ -10,6 +10,13 @@ fi
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 . /opt/conda/etc/profile.d/conda.sh
 
 rapids-logger "Configuring conda strict channel priority"
diff --git a/ci/test_notebooks.sh b/ci/test_notebooks.sh
index 22c41af84c..8e0df1b4df 100755
--- a/ci/test_notebooks.sh
+++ b/ci/test_notebooks.sh
@@ -5,6 +5,13 @@
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 . /opt/conda/etc/profile.d/conda.sh
 
 rapids-logger "Configuring conda strict channel priority"
diff --git a/ci/test_python.sh b/ci/test_python.sh
index 4f91c83334..aec654ad17 100755
--- a/ci/test_python.sh
+++ b/ci/test_python.sh
@@ -5,6 +5,13 @@
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 . /opt/conda/etc/profile.d/conda.sh
 
 rapids-logger "Configuring conda strict channel priority"
diff --git a/ci/test_self_hosted_service.sh b/ci/test_self_hosted_service.sh
index 601b45326b..c9b7d509b6 100755
--- a/ci/test_self_hosted_service.sh
+++ b/ci/test_self_hosted_service.sh
@@ -5,6 +5,13 @@
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 source rapids-init-pip
 
 # Download the cuopt built in the previous step
diff --git a/ci/test_skills_assets.sh b/ci/test_skills_assets.sh
index c75645cb93..ccb5161a11 100755
--- a/ci/test_skills_assets.sh
+++ b/ci/test_skills_assets.sh
@@ -10,6 +10,13 @@
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 # Use rapids-logger in CI; fall back to echo for local testing
 if command -v rapids-logger &>/dev/null; then
   log() { rapids-logger "$*"; }
diff --git a/ci/test_wheel_cuopt.sh b/ci/test_wheel_cuopt.sh
index a327082e83..33a5300581 100755
--- a/ci/test_wheel_cuopt.sh
+++ b/ci/test_wheel_cuopt.sh
@@ -5,6 +5,13 @@
 
 set -euo pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 # sets up a constraints file for 'pip' and puts its location in an exported variable PIP_EXPORT,
 # so those constraints will affect all future 'pip install' calls
 source rapids-init-pip
diff --git a/ci/test_wheel_cuopt_server.sh b/ci/test_wheel_cuopt_server.sh
index a76969b965..19c4bf7c1a 100755
--- a/ci/test_wheel_cuopt_server.sh
+++ b/ci/test_wheel_cuopt_server.sh
@@ -5,6 +5,13 @@
 
 set -eou pipefail
 
+_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
+# shellcheck source=ci/cuopt_coredumps.sh
+source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
+cuopt_enable_coredumps
+trap 'cuopt_collect_coredumps || true' EXIT
+unset _CUOPT_CI_DIR
+
 source rapids-init-pip
 
 # Download the packages built in the previous step

From 2fd437fc2b2e0a03a6eeef246fc8a0502b187a06 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Wed, 1 Apr 2026 15:29:06 -0500
Subject: [PATCH 02/18] fix style

---
 ci/test_cpp.sh          | 2 +-
 ci/test_cpp_memcheck.sh | 2 +-
 ci/test_notebooks.sh    | 2 +-
 3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index 570f4816d9..bd65f927a3 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# SPDX-FileCopyrightText: Copyright (c) 2023-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 set -euo pipefail
diff --git a/ci/test_cpp_memcheck.sh b/ci/test_cpp_memcheck.sh
index 48199eecef..d9ddbc7edd 100755
--- a/ci/test_cpp_memcheck.sh
+++ b/ci/test_cpp_memcheck.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# SPDX-FileCopyrightText: Copyright (c) 2023-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 if [[ "$(date +%A)" != "Friday" ]]; then
diff --git a/ci/test_notebooks.sh b/ci/test_notebooks.sh
index 8e0df1b4df..b7897e4032 100755
--- a/ci/test_notebooks.sh
+++ b/ci/test_notebooks.sh
@@ -1,6 +1,6 @@
 #!/bin/bash
 
-# SPDX-FileCopyrightText: Copyright (c) 2023-2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2023-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 
 set -euo pipefail

From 0da2a0de87acf39c0c734720f1cd5d9db4286357 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Wed, 1 Apr 2026 15:33:19 -0500
Subject: [PATCH 03/18] add core dump test

---
 ci/run_ctests.sh                             | 17 ++++++++++
 cpp/tests/utilities/CMakeLists.txt           |  3 ++
 cpp/tests/utilities/coredump_sanity_test.cpp | 34 ++++++++++++++++++++
 3 files changed, 54 insertions(+)
 create mode 100644 cpp/tests/utilities/coredump_sanity_test.cpp

diff --git a/ci/run_ctests.sh b/ci/run_ctests.sh
index fc1de8e1b4..0287fcbc61 100755
--- a/ci/run_ctests.sh
+++ b/ci/run_ctests.sh
@@ -21,6 +21,23 @@ else
     exit 1
 fi
 
+# Run first: intentional SIGSEGV to validate core dump collection (ci/cuopt_coredumps.sh).
+# Expect a non-zero exit (e.g. 139). The same binary is invoked again in the loop without
+# CUOPT_TEST_COREDUMP and skips the fatal case.
+if [[ -x "${GTEST_DIR}/COREDUMP_SANITY_TEST" ]]; then
+  echo "Running COREDUMP_SANITY_TEST with CUOPT_TEST_COREDUMP=1 (expected fatal signal)"
+  set +e
+  CUOPT_TEST_COREDUMP=1 "${GTEST_DIR}/COREDUMP_SANITY_TEST" "$@"
+  _coredump_ret=$?
+  set -e
+  if [[ "${_coredump_ret}" -eq 0 ]]; then
+    echo "ERROR: COREDUMP_SANITY_TEST exited 0 with CUOPT_TEST_COREDUMP=1; expected crash" >&2
+    exit 1
+  fi
+else
+  echo "Skipping COREDUMP_SANITY_TEST (binary not found)"
+fi
+
 for gt in "${GTEST_DIR}"/*_TEST; do
     test_name=$(basename "${gt}")
     echo "Running gtest ${test_name}"
diff --git a/cpp/tests/utilities/CMakeLists.txt b/cpp/tests/utilities/CMakeLists.txt
index 5f9e6d5e82..73020cf0a9 100644
--- a/cpp/tests/utilities/CMakeLists.txt
+++ b/cpp/tests/utilities/CMakeLists.txt
@@ -5,3 +5,6 @@
 
 # Add CLI end-to-end test
 ConfigureTest(CLI_TEST test_cli.cpp)
+
+# Opt-in SIGSEGV for validating core dump collection (CUOPT_TEST_COREDUMP=1)
+ConfigureTest(COREDUMP_SANITY_TEST coredump_sanity_test.cpp)
diff --git a/cpp/tests/utilities/coredump_sanity_test.cpp b/cpp/tests/utilities/coredump_sanity_test.cpp
new file mode 100644
index 0000000000..31fafc61f7
--- /dev/null
+++ b/cpp/tests/utilities/coredump_sanity_test.cpp
@@ -0,0 +1,34 @@
+/* clang-format off */
+/*
+ * SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0
+ */
+/* clang-format on */
+
+#include <gtest/gtest.h>
+
+#include <csignal>
+#include <cstdlib>
+#include <cstring>
+
+namespace {
+
+bool coredump_env_enabled()
+{
+  const char* v = std::getenv("CUOPT_TEST_COREDUMP");
+  if (v == nullptr || v[0] == '\0') { return false; }
+  return std::strcmp(v, "0") != 0;
+}
+
+}  // namespace
+
+// Opt-in crash to validate CI core dump collection (see ci/cuopt_coredumps.sh).
+// Normal CI: skipped. To reproduce locally or in a one-off job:
+//   CUOPT_TEST_COREDUMP=1 ulimit -c unlimited ./COREDUMP_SANITY_TEST
+TEST(CoredumpSanity, IntentionalSegfaultWhenEnvSet)
+{
+  if (!coredump_env_enabled()) {
+    GTEST_SKIP() << "Set CUOPT_TEST_COREDUMP=1 to intentionally SIGSEGV for core dump checks.";
+  }
+  std::raise(SIGSEGV);
+}

From 5f44aac20985ea0a678c2c27f5b50613047d80b6 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Wed, 1 Apr 2026 15:34:04 -0500
Subject: [PATCH 04/18] testing

---
 cpp/tests/utilities/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpp/tests/utilities/CMakeLists.txt b/cpp/tests/utilities/CMakeLists.txt
index 73020cf0a9..89958f32e1 100644
--- a/cpp/tests/utilities/CMakeLists.txt
+++ b/cpp/tests/utilities/CMakeLists.txt
@@ -1,5 +1,5 @@
 # cmake-format: off
-# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 # cmake-format: on
 

From 7276e858bee48edcc73907ae77fb6d58768f6aae Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 11:56:35 -0500
Subject: [PATCH 05/18] enable core dump for all

---
 ci/cuopt_coredumps.sh          | 174 +++++++++++++++++++++++++++++++--
 ci/run_ctests.sh               |   8 +-
 ci/test_cpp.sh                 |  13 ++-
 ci/test_cpp_memcheck.sh        |   1 +
 ci/test_notebooks.sh           |   1 +
 ci/test_python.sh              |   1 +
 ci/test_self_hosted_service.sh |   1 +
 ci/test_skills_assets.sh       |   1 +
 ci/test_wheel_cuopt.sh         |   1 +
 ci/test_wheel_cuopt_server.sh  |   1 +
 10 files changed, 190 insertions(+), 12 deletions(-)

diff --git a/ci/cuopt_coredumps.sh b/ci/cuopt_coredumps.sh
index 650382174b..f5d294d9f4 100644
--- a/ci/cuopt_coredumps.sh
+++ b/ci/cuopt_coredumps.sh
@@ -4,37 +4,197 @@
 # SPDX-License-Identifier: Apache-2.0
 
 # Enable core dumps during CI test scripts and collect files into
-# ${RAPIDS_ARTIFACTS_DIR}/coredumps so rapids-upload-artifacts-dir uploads them (S3).
+# ${RAPIDS_ARTIFACTS_DIR}/${CUOPT_GDB_CORE_ARTIFACT_DIR} so rapids-upload-artifacts-dir
+# uploads them to S3 as:
+#   {rapids-matrix-prefix}.{cuopt-gdb-cores_JOB_cudaVER_pyVER_arch_BUILDTYPE}
+# (tarball of that directory). The trailing segment includes a job label, resolved in order:
+#   1) CUOPT_CI_JOB_LABEL if set (workflow/setter can export the real GitHub job id).
+#   2) GITHUB_JOB if it looks like a caller job id (not generic RAPIDS callee ids such as tests).
+#   3) The ci/test_*.sh that sourced this file: label derived by naming rules (new drivers need
+#      no edits here — e.g. test_foo.sh → conda-foo-tests, test_wheel_bar.sh → wheel-bar-tests).
+# Then CUDA / Python / arch / build_type from RAPIDS CI env.
 #
-# Shells: source this file from repo ci/ scripts, then call cuopt_enable_coredumps
-# and trap cuopt_collect_coredumps on EXIT.
+# Coredump smoke (fails the job immediately after setup so you can verify artifacts):
+#   • On GitHub Actions (GITHUB_ACTIONS=true): runs unless CUOPT_CI_COREDUMP_SMOKE is 0|false|no|off.
+#   • Elsewhere: runs only if CUOPT_CI_COREDUMP_SMOKE is 1|true|yes|on (local ad-hoc testing).
+#   cuopt_coredump_smoke_fail_job_if_enabled SIGSEGVs a child, EXIT trap collects cores, exit 139.
+#
+# Shells: source this file from repo ci/ scripts, then call cuopt_enable_coredumps and trap
+# cuopt_collect_coredumps on EXIT, then cuopt_coredump_smoke_fail_job_if_enabled.
+
+# Set in cuopt_enable_coredumps; collect reuses when non-empty.
+CUOPT_GDB_CORE_ARTIFACT_DIR=
+
+# Reusable RAPIDS workflows often run a job literally named "tests" / "build" — not unique.
+cuopt__github_job_is_generic() {
+  case "${1:-}" in
+    "" | tests | build | compute-matrix | prepare | package) return 0 ;;
+    *) return 1 ;;
+  esac
+}
+
+# test_cpp.sh → conda-cpp-tests; test_wheel_cuopt_server.sh → wheel-cuopt-server-tests; etc.
+cuopt__job_label_from_entry_script_basename() {
+  local b="$1"
+  b="${b%.sh}"
+  case "$b" in
+    test_wheel_*)
+      b="${b#test_wheel_}"
+      echo "wheel-${b//_/-}-tests"
+      ;;
+    test_self_hosted_*)
+      b="${b#test_self_hosted_}"
+      echo "self-hosted-${b//_/-}-tests"
+      ;;
+    test_skills_*)
+      b="${b#test_skills_}"
+      echo "conda-skills-${b//_/-}"
+      ;;
+    test_*memcheck)
+      b="${b#test_}"
+      echo "conda-${b//_/-}"
+      ;;
+    test_*)
+      b="${b#test_}"
+      echo "conda-${b//_/-}-tests"
+      ;;
+    *)
+      echo "unknown-job"
+      ;;
+  esac
+}
+
+cuopt__find_ci_entry_test_script_basename() {
+  local i f base
+  for ((i = 0; i < ${#BASH_SOURCE[@]}; i++)); do
+    f="${BASH_SOURCE[$i]}"
+    base="$(basename "${f}")"
+    [[ "${base}" == "cuopt_coredumps.sh" ]] && continue
+    case "${base}" in
+      test_*.sh) echo "${base}"; return ;;
+    esac
+  done
+  echo ""
+}
+
+cuopt__infer_ci_job_label_from_call_stack() {
+  local nb
+  nb="$(cuopt__find_ci_entry_test_script_basename)"
+  if [[ -n "${nb}" ]]; then
+    cuopt__job_label_from_entry_script_basename "${nb}"
+    return
+  fi
+  echo "unknown-job"
+}
+
+cuopt__resolve_ci_job_label() {
+  if [[ -n "${CUOPT_CI_JOB_LABEL:-}" ]]; then
+    echo "${CUOPT_CI_JOB_LABEL}"
+    return
+  fi
+  if [[ -n "${GITHUB_JOB:-}" ]] && ! cuopt__github_job_is_generic "${GITHUB_JOB}"; then
+    echo "${GITHUB_JOB}"
+    return
+  fi
+  cuopt__infer_ci_job_label_from_call_stack
+}
+
+cuopt__gdb_core_artifact_basename() {
+  local job cuda_ver py_ver arch_ bt
+  job="$(cuopt__resolve_ci_job_label)"
+  job="${job//[^a-zA-Z0-9_-]/_}"
+  cuda_ver="${RAPIDS_CUDA_VERSION:-unknown}"
+  cuda_ver="${cuda_ver//[^a-zA-Z0-9._-]/_}"
+  py_ver="${RAPIDS_PY_VERSION:-na}"
+  py_ver="${py_ver//[^a-zA-Z0-9._-]/_}"
+  arch_="$(arch 2>/dev/null || true)"
+  [[ -z "${arch_}" ]] && arch_="$(uname -m)"
+  arch_="${arch_//[^a-zA-Z0-9_-]/_}"
+  bt="${RAPIDS_BUILD_TYPE:-na}"
+  bt="${bt//[^a-zA-Z0-9_-]/_}"
+  echo "cuopt-gdb-cores_${job}_cuda${cuda_ver}_py${py_ver}_${arch_}_${bt}"
+}
 
 cuopt_enable_coredumps() {
   local ws base pattern
   ws="${GITHUB_WORKSPACE:-${PWD}}"
   base="${RAPIDS_ARTIFACTS_DIR:-${ws}/artifacts}"
-  export CUOPT_COREDUMP_DIR="${base}/coredumps"
+  export CUOPT_CI_JOB_LABEL="$(cuopt__resolve_ci_job_label)"
+  CUOPT_GDB_CORE_ARTIFACT_DIR="$(cuopt__gdb_core_artifact_basename)"
+  export CUOPT_GDB_CORE_ARTIFACT_DIR
+  export CUOPT_COREDUMP_DIR="${base}/${CUOPT_GDB_CORE_ARTIFACT_DIR}"
   mkdir -p "${CUOPT_COREDUMP_DIR}"
 
+  local pattern_target="${CUOPT_COREDUMP_DIR}/core.%e.%p.%t"
+
+  # Raise soft limit to match hard limit when possible (some shells default to 0).
   ulimit -c unlimited 2>/dev/null || true
+  ulimit -H -c unlimited 2>/dev/null || true
 
+  # When unset, ask the kernel for broad core dump contents (Linux 4.6+; ignored elsewhere).
+  if [[ -z "${COREDUMP_FILTER:-}" ]]; then
+    export COREDUMP_FILTER=0xff
+  fi
+
+  # Prefer writing cores as files under CUOPT_COREDUMP_DIR (often fails in unprivileged Docker).
   if [[ -w /proc/sys/kernel/core_pattern ]]; then
-    echo "${CUOPT_COREDUMP_DIR}/core.%e.%p.%t" >/proc/sys/kernel/core_pattern 2>/dev/null || true
+    echo "${pattern_target}" >/proc/sys/kernel/core_pattern 2>/dev/null || true
+  fi
+  if command -v sysctl >/dev/null 2>&1; then
+    sysctl -q -w "kernel.core_pattern=${pattern_target}" 2>/dev/null || true
   fi
 
   pattern="$(cat /proc/sys/kernel/core_pattern 2>/dev/null || echo n/a)"
   if declare -F rapids-logger &>/dev/null; then
     rapids-logger "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit -c=$(ulimit -c) core_pattern=${pattern}"
+    if [[ "${pattern}" == \|* ]]; then
+      rapids-logger "WARNING: core_pattern pipes to a collector (e.g. apport); cores may not appear as files under ${CUOPT_COREDUMP_DIR}. Use a writable core_pattern or a privileged runner if needed."
+    fi
   else
     echo "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit -c=$(ulimit -c) core_pattern=${pattern}"
+    if [[ "${pattern}" == \|* ]]; then
+      echo "WARNING: core_pattern pipes to a collector; files may not land in ${CUOPT_COREDUMP_DIR}" >&2
+    fi
   fi
 }
 
+# Deliberate SIGSEGV in a subprocess, then exit so CI fails and EXIT trap still runs collection.
+cuopt_coredump_smoke_fail_job_if_enabled() {
+  case "${CUOPT_CI_COREDUMP_SMOKE:-}" in
+    0 | false | FALSE | no | NO | off | OFF) return 0 ;;
+  esac
+
+  local run_smoke=0
+  if [[ "${GITHUB_ACTIONS:-}" == "true" ]]; then
+    run_smoke=1
+  fi
+  case "${CUOPT_CI_COREDUMP_SMOKE:-}" in
+    1 | true | TRUE | yes | YES | on | ON) run_smoke=1 ;;
+  esac
+  if [[ "${run_smoke}" -eq 0 ]]; then
+    return 0
+  fi
+
+  if declare -F rapids-logger &>/dev/null; then
+    rapids-logger "Coredump smoke: SIGSEGV in child bash (GITHUB_ACTIONS=${GITHUB_ACTIONS:-unset}, CUOPT_CI_COREDUMP_SMOKE=${CUOPT_CI_COREDUMP_SMOKE:-unset}); exiting 139"
+  else
+    echo "Coredump smoke: SIGSEGV child; exiting 139 (GITHUB_ACTIONS=${GITHUB_ACTIONS:-unset})" >&2
+  fi
+  # Crash the child only: if the main script died from SIGSEGV, the EXIT trap would not run.
+  bash -c 'kill -SEGV "$$"' || true
+  # Brief pause so the kernel can finish writing the core file before the parent exits.
+  sleep 0.2
+  exit 139
+}
+
 cuopt_collect_coredumps() {
   local ws base dest n_before n_after f rel dest_name dest_path
   ws="${GITHUB_WORKSPACE:-${PWD}}"
   base="${RAPIDS_ARTIFACTS_DIR:-${ws}/artifacts}"
-  dest="${base}/coredumps"
+  if [[ -z "${CUOPT_GDB_CORE_ARTIFACT_DIR:-}" ]]; then
+    CUOPT_GDB_CORE_ARTIFACT_DIR="$(cuopt__gdb_core_artifact_basename)"
+  fi
+  dest="${base}/${CUOPT_GDB_CORE_ARTIFACT_DIR}"
   mkdir -p "${dest}"
 
   n_before="$(find "${dest}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
@@ -56,7 +216,7 @@ cuopt_collect_coredumps() {
     cp -a "${f}" "${dest_path}" 2>/dev/null || true
   done < <(
     find "${ws}" \
-      \( -path '*/.git/*' -o -path '*/opt/conda/*' -o -path '*/conda_pkgs/*' -o -path '*/artifacts/coredumps/*' \) -prune -o \
+      \( -path '*/.git/*' -o -path '*/opt/conda/*' -o -path '*/conda_pkgs/*' -o -path "${dest}/*" \) -prune -o \
       \( -name 'core' -o -name 'core.*' \) -type f -print0 2>/dev/null
   )
 
diff --git a/ci/run_ctests.sh b/ci/run_ctests.sh
index 0287fcbc61..d808ed5403 100755
--- a/ci/run_ctests.sh
+++ b/ci/run_ctests.sh
@@ -38,11 +38,17 @@ else
   echo "Skipping COREDUMP_SANITY_TEST (binary not found)"
 fi
 
+shopt -s nullglob
 for gt in "${GTEST_DIR}"/*_TEST; do
     test_name=$(basename "${gt}")
     echo "Running gtest ${test_name}"
-    "${gt}" "$@"
+    if ! "${gt}" "$@"; then
+      _g_rc=$?
+      echo "ERROR: gtest ${test_name} failed (exit ${_g_rc}); stopping run_ctests.sh" >&2
+      exit "${_g_rc}"
+    fi
 done
+shopt -u nullglob
 
 # Run C_API_TEST with CPU memory for local solves (excluding time limit tests)
 if [ -x "${GTEST_DIR}/C_API_TEST" ]; then
diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index bd65f927a3..d391f47e09 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -11,6 +11,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
@@ -51,8 +52,6 @@ pushd "${RAPIDS_DATASET_ROOT_DIR}"
 ./get_test_data.sh
 popd
 
-EXITCODE=0
-trap "EXITCODE=1" ERR
 set +e
 
 # Run gtests from libcuopt-tests package
@@ -60,6 +59,12 @@ export GTEST_OUTPUT=xml:${RAPIDS_TESTS_DIR}/
 
 rapids-logger "Run gtests"
 timeout 40m ./ci/run_ctests.sh
+EXITCODE=$?
+set -e
 
-rapids-logger "Test script exiting with value: $EXITCODE"
-exit ${EXITCODE}
+if [[ "${EXITCODE}" -ne 0 ]]; then
+  rapids-logger "run_ctests.sh failed (exit ${EXITCODE}); skipping remaining steps"
+fi
+
+rapids-logger "Test script exiting with value: ${EXITCODE}"
+exit "${EXITCODE}"
diff --git a/ci/test_cpp_memcheck.sh b/ci/test_cpp_memcheck.sh
index d9ddbc7edd..aab3bfb6b8 100755
--- a/ci/test_cpp_memcheck.sh
+++ b/ci/test_cpp_memcheck.sh
@@ -16,6 +16,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_notebooks.sh b/ci/test_notebooks.sh
index b7897e4032..424e8a6cd3 100755
--- a/ci/test_notebooks.sh
+++ b/ci/test_notebooks.sh
@@ -11,6 +11,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_python.sh b/ci/test_python.sh
index aec654ad17..6e13f19032 100755
--- a/ci/test_python.sh
+++ b/ci/test_python.sh
@@ -11,6 +11,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_self_hosted_service.sh b/ci/test_self_hosted_service.sh
index c9b7d509b6..7150356764 100755
--- a/ci/test_self_hosted_service.sh
+++ b/ci/test_self_hosted_service.sh
@@ -11,6 +11,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 source rapids-init-pip
 
diff --git a/ci/test_skills_assets.sh b/ci/test_skills_assets.sh
index ccb5161a11..ec934b079d 100755
--- a/ci/test_skills_assets.sh
+++ b/ci/test_skills_assets.sh
@@ -16,6 +16,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 # Use rapids-logger in CI; fall back to echo for local testing
 if command -v rapids-logger &>/dev/null; then
diff --git a/ci/test_wheel_cuopt.sh b/ci/test_wheel_cuopt.sh
index 33a5300581..1b8d83a176 100755
--- a/ci/test_wheel_cuopt.sh
+++ b/ci/test_wheel_cuopt.sh
@@ -11,6 +11,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 # sets up a constraints file for 'pip' and puts its location in an exported variable PIP_EXPORT,
 # so those constraints will affect all future 'pip install' calls
diff --git a/ci/test_wheel_cuopt_server.sh b/ci/test_wheel_cuopt_server.sh
index 19c4bf7c1a..62f4a5109c 100755
--- a/ci/test_wheel_cuopt_server.sh
+++ b/ci/test_wheel_cuopt_server.sh
@@ -11,6 +11,7 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
+cuopt_coredump_smoke_fail_job_if_enabled
 
 source rapids-init-pip
 

From 33ab5f4b137d4d11a84dbea7c8cc1b3c91fe60ed Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 11:59:05 -0500
Subject: [PATCH 06/18] style

---
 ci/cuopt_coredumps.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ci/cuopt_coredumps.sh b/ci/cuopt_coredumps.sh
index f5d294d9f4..26fe7247a1 100644
--- a/ci/cuopt_coredumps.sh
+++ b/ci/cuopt_coredumps.sh
@@ -119,7 +119,8 @@ cuopt_enable_coredumps() {
   local ws base pattern
   ws="${GITHUB_WORKSPACE:-${PWD}}"
   base="${RAPIDS_ARTIFACTS_DIR:-${ws}/artifacts}"
-  export CUOPT_CI_JOB_LABEL="$(cuopt__resolve_ci_job_label)"
+  CUOPT_CI_JOB_LABEL="$(cuopt__resolve_ci_job_label)"
+  export CUOPT_CI_JOB_LABEL
   CUOPT_GDB_CORE_ARTIFACT_DIR="$(cuopt__gdb_core_artifact_basename)"
   export CUOPT_GDB_CORE_ARTIFACT_DIR
   export CUOPT_COREDUMP_DIR="${base}/${CUOPT_GDB_CORE_ARTIFACT_DIR}"

From 484d1b87402c5edf0c5a9a36247b1c33bf3a9cdd Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 13:32:30 -0500
Subject: [PATCH 07/18] check fixes

---
 ci/cuopt_coredumps.sh | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/ci/cuopt_coredumps.sh b/ci/cuopt_coredumps.sh
index 26fe7247a1..c5e815c9dd 100644
--- a/ci/cuopt_coredumps.sh
+++ b/ci/cuopt_coredumps.sh
@@ -7,9 +7,12 @@
 # ${RAPIDS_ARTIFACTS_DIR}/${CUOPT_GDB_CORE_ARTIFACT_DIR} so rapids-upload-artifacts-dir
 # uploads them to S3 as:
 #   {rapids-matrix-prefix}.{cuopt-gdb-cores_JOB_cudaVER_pyVER_arch_BUILDTYPE}
-# (tarball of that directory). The trailing segment includes a job label, resolved in order:
+# RAPIDS rapids-upload-to-s3 tgz-streams each directory (gzip-compressed tar); the object
+# name often has no .tar.gz suffix in listings, but downloads are still archives. Very small
+# sizes (~100 B) usually mean an almost-empty archive (no core files landed on disk). The
+# trailing segment includes a job label, resolved in order:
 #   1) CUOPT_CI_JOB_LABEL if set (workflow/setter can export the real GitHub job id).
-#   2) GITHUB_JOB if it looks like a caller job id (not generic RAPIDS callee ids such as tests).
+#   2) GITHUB_JOB if it looks like a caller job id (not generic RAPIDS callee ids such as tests/test).
 #   3) The ci/test_*.sh that sourced this file: label derived by naming rules (new drivers need
 #      no edits here — e.g. test_foo.sh → conda-foo-tests, test_wheel_bar.sh → wheel-bar-tests).
 # Then CUDA / Python / arch / build_type from RAPIDS CI env.
@@ -25,10 +28,12 @@
 # Set in cuopt_enable_coredumps; collect reuses when non-empty.
 CUOPT_GDB_CORE_ARTIFACT_DIR=
 
-# Reusable RAPIDS workflows often run a job literally named "tests" / "build" — not unique.
+# Reusable RAPIDS workflows often use non-unique job ids ("tests", "test", "build", …).
+# GITHUB_JOB=test (singular) is common; treating it as meaningful produced labels like
+# "test" and hid script-based names (wheel-cuopt-tests, conda-cpp-tests).
 cuopt__github_job_is_generic() {
   case "${1:-}" in
-    "" | tests | build | compute-matrix | prepare | package) return 0 ;;
+    "" | test | tests | build | compute-matrix | prepare | package) return 0 ;;
     *) return 1 ;;
   esac
 }

From 43b91f357d8b8b6144c4ba76b08edf43871f7d51 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 15:47:32 -0500
Subject: [PATCH 08/18] remove testing

---
 ci/cuopt_coredumps.sh              | 36 +-----------------------------
 ci/run_ctests.sh                   | 17 --------------
 ci/test_cpp.sh                     |  1 -
 cpp/tests/utilities/CMakeLists.txt |  3 ---
 4 files changed, 1 insertion(+), 56 deletions(-)

diff --git a/ci/cuopt_coredumps.sh b/ci/cuopt_coredumps.sh
index c5e815c9dd..44b2e7030a 100644
--- a/ci/cuopt_coredumps.sh
+++ b/ci/cuopt_coredumps.sh
@@ -17,13 +17,8 @@
 #      no edits here — e.g. test_foo.sh → conda-foo-tests, test_wheel_bar.sh → wheel-bar-tests).
 # Then CUDA / Python / arch / build_type from RAPIDS CI env.
 #
-# Coredump smoke (fails the job immediately after setup so you can verify artifacts):
-#   • On GitHub Actions (GITHUB_ACTIONS=true): runs unless CUOPT_CI_COREDUMP_SMOKE is 0|false|no|off.
-#   • Elsewhere: runs only if CUOPT_CI_COREDUMP_SMOKE is 1|true|yes|on (local ad-hoc testing).
-#   cuopt_coredump_smoke_fail_job_if_enabled SIGSEGVs a child, EXIT trap collects cores, exit 139.
-#
 # Shells: source this file from repo ci/ scripts, then call cuopt_enable_coredumps and trap
-# cuopt_collect_coredumps on EXIT, then cuopt_coredump_smoke_fail_job_if_enabled.
+# cuopt_collect_coredumps on EXIT.
 
 # Set in cuopt_enable_coredumps; collect reuses when non-empty.
 CUOPT_GDB_CORE_ARTIFACT_DIR=
@@ -164,35 +159,6 @@ cuopt_enable_coredumps() {
   fi
 }
 
-# Deliberate SIGSEGV in a subprocess, then exit so CI fails and EXIT trap still runs collection.
-cuopt_coredump_smoke_fail_job_if_enabled() {
-  case "${CUOPT_CI_COREDUMP_SMOKE:-}" in
-    0 | false | FALSE | no | NO | off | OFF) return 0 ;;
-  esac
-
-  local run_smoke=0
-  if [[ "${GITHUB_ACTIONS:-}" == "true" ]]; then
-    run_smoke=1
-  fi
-  case "${CUOPT_CI_COREDUMP_SMOKE:-}" in
-    1 | true | TRUE | yes | YES | on | ON) run_smoke=1 ;;
-  esac
-  if [[ "${run_smoke}" -eq 0 ]]; then
-    return 0
-  fi
-
-  if declare -F rapids-logger &>/dev/null; then
-    rapids-logger "Coredump smoke: SIGSEGV in child bash (GITHUB_ACTIONS=${GITHUB_ACTIONS:-unset}, CUOPT_CI_COREDUMP_SMOKE=${CUOPT_CI_COREDUMP_SMOKE:-unset}); exiting 139"
-  else
-    echo "Coredump smoke: SIGSEGV child; exiting 139 (GITHUB_ACTIONS=${GITHUB_ACTIONS:-unset})" >&2
-  fi
-  # Crash the child only: if the main script died from SIGSEGV, the EXIT trap would not run.
-  bash -c 'kill -SEGV "$$"' || true
-  # Brief pause so the kernel can finish writing the core file before the parent exits.
-  sleep 0.2
-  exit 139
-}
-
 cuopt_collect_coredumps() {
   local ws base dest n_before n_after f rel dest_name dest_path
   ws="${GITHUB_WORKSPACE:-${PWD}}"
diff --git a/ci/run_ctests.sh b/ci/run_ctests.sh
index d808ed5403..01508ffc01 100755
--- a/ci/run_ctests.sh
+++ b/ci/run_ctests.sh
@@ -21,23 +21,6 @@ else
     exit 1
 fi
 
-# Run first: intentional SIGSEGV to validate core dump collection (ci/cuopt_coredumps.sh).
-# Expect a non-zero exit (e.g. 139). The same binary is invoked again in the loop without
-# CUOPT_TEST_COREDUMP and skips the fatal case.
-if [[ -x "${GTEST_DIR}/COREDUMP_SANITY_TEST" ]]; then
-  echo "Running COREDUMP_SANITY_TEST with CUOPT_TEST_COREDUMP=1 (expected fatal signal)"
-  set +e
-  CUOPT_TEST_COREDUMP=1 "${GTEST_DIR}/COREDUMP_SANITY_TEST" "$@"
-  _coredump_ret=$?
-  set -e
-  if [[ "${_coredump_ret}" -eq 0 ]]; then
-    echo "ERROR: COREDUMP_SANITY_TEST exited 0 with CUOPT_TEST_COREDUMP=1; expected crash" >&2
-    exit 1
-  fi
-else
-  echo "Skipping COREDUMP_SANITY_TEST (binary not found)"
-fi
-
 shopt -s nullglob
 for gt in "${GTEST_DIR}"/*_TEST; do
     test_name=$(basename "${gt}")
diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index d391f47e09..1caaed4c54 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -11,7 +11,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/cpp/tests/utilities/CMakeLists.txt b/cpp/tests/utilities/CMakeLists.txt
index 89958f32e1..75c3805c6e 100644
--- a/cpp/tests/utilities/CMakeLists.txt
+++ b/cpp/tests/utilities/CMakeLists.txt
@@ -5,6 +5,3 @@
 
 # Add CLI end-to-end test
 ConfigureTest(CLI_TEST test_cli.cpp)
-
-# Opt-in SIGSEGV for validating core dump collection (CUOPT_TEST_COREDUMP=1)
-ConfigureTest(COREDUMP_SANITY_TEST coredump_sanity_test.cpp)

From 75fc79ae1bbe7fea694171f5ad68566f21254202 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 15:48:22 -0500
Subject: [PATCH 09/18] fix

---
 cpp/tests/utilities/CMakeLists.txt | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/cpp/tests/utilities/CMakeLists.txt b/cpp/tests/utilities/CMakeLists.txt
index 75c3805c6e..5f9e6d5e82 100644
--- a/cpp/tests/utilities/CMakeLists.txt
+++ b/cpp/tests/utilities/CMakeLists.txt
@@ -1,5 +1,5 @@
 # cmake-format: off
-# SPDX-FileCopyrightText: Copyright (c) 2025-2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
+# SPDX-FileCopyrightText: Copyright (c) 2025 NVIDIA CORPORATION & AFFILIATES. All rights reserved.
 # SPDX-License-Identifier: Apache-2.0
 # cmake-format: on
 

From c05f23ed8dfac89e6f2baf25ede2c7fc6d67e4c2 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 15:52:38 -0500
Subject: [PATCH 10/18] remove testing

---
 ci/test_cpp_memcheck.sh                      |  1 -
 ci/test_notebooks.sh                         |  1 -
 ci/test_python.sh                            |  1 -
 ci/test_self_hosted_service.sh               |  1 -
 ci/test_skills_assets.sh                     |  1 -
 ci/test_wheel_cuopt.sh                       |  1 -
 ci/test_wheel_cuopt_server.sh                |  1 -
 cpp/tests/utilities/coredump_sanity_test.cpp | 34 --------------------
 8 files changed, 41 deletions(-)
 delete mode 100644 cpp/tests/utilities/coredump_sanity_test.cpp

diff --git a/ci/test_cpp_memcheck.sh b/ci/test_cpp_memcheck.sh
index aab3bfb6b8..d9ddbc7edd 100755
--- a/ci/test_cpp_memcheck.sh
+++ b/ci/test_cpp_memcheck.sh
@@ -16,7 +16,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_notebooks.sh b/ci/test_notebooks.sh
index 424e8a6cd3..b7897e4032 100755
--- a/ci/test_notebooks.sh
+++ b/ci/test_notebooks.sh
@@ -11,7 +11,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_python.sh b/ci/test_python.sh
index 6e13f19032..aec654ad17 100755
--- a/ci/test_python.sh
+++ b/ci/test_python.sh
@@ -11,7 +11,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_self_hosted_service.sh b/ci/test_self_hosted_service.sh
index 7150356764..c9b7d509b6 100755
--- a/ci/test_self_hosted_service.sh
+++ b/ci/test_self_hosted_service.sh
@@ -11,7 +11,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 source rapids-init-pip
 
diff --git a/ci/test_skills_assets.sh b/ci/test_skills_assets.sh
index ec934b079d..ccb5161a11 100755
--- a/ci/test_skills_assets.sh
+++ b/ci/test_skills_assets.sh
@@ -16,7 +16,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 # Use rapids-logger in CI; fall back to echo for local testing
 if command -v rapids-logger &>/dev/null; then
diff --git a/ci/test_wheel_cuopt.sh b/ci/test_wheel_cuopt.sh
index 1b8d83a176..33a5300581 100755
--- a/ci/test_wheel_cuopt.sh
+++ b/ci/test_wheel_cuopt.sh
@@ -11,7 +11,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 # sets up a constraints file for 'pip' and puts its location in an exported variable PIP_EXPORT,
 # so those constraints will affect all future 'pip install' calls
diff --git a/ci/test_wheel_cuopt_server.sh b/ci/test_wheel_cuopt_server.sh
index 62f4a5109c..19c4bf7c1a 100755
--- a/ci/test_wheel_cuopt_server.sh
+++ b/ci/test_wheel_cuopt_server.sh
@@ -11,7 +11,6 @@ source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
 cuopt_enable_coredumps
 trap 'cuopt_collect_coredumps || true' EXIT
 unset _CUOPT_CI_DIR
-cuopt_coredump_smoke_fail_job_if_enabled
 
 source rapids-init-pip
 
diff --git a/cpp/tests/utilities/coredump_sanity_test.cpp b/cpp/tests/utilities/coredump_sanity_test.cpp
deleted file mode 100644
index 31fafc61f7..0000000000
--- a/cpp/tests/utilities/coredump_sanity_test.cpp
+++ /dev/null
@@ -1,34 +0,0 @@
-/* clang-format off */
-/*
- * SPDX-FileCopyrightText: Copyright (c) 2026, NVIDIA CORPORATION & AFFILIATES. All rights reserved.
- * SPDX-License-Identifier: Apache-2.0
- */
-/* clang-format on */
-
-#include <gtest/gtest.h>
-
-#include <csignal>
-#include <cstdlib>
-#include <cstring>
-
-namespace {
-
-bool coredump_env_enabled()
-{
-  const char* v = std::getenv("CUOPT_TEST_COREDUMP");
-  if (v == nullptr || v[0] == '\0') { return false; }
-  return std::strcmp(v, "0") != 0;
-}
-
-}  // namespace
-
-// Opt-in crash to validate CI core dump collection (see ci/cuopt_coredumps.sh).
-// Normal CI: skipped. To reproduce locally or in a one-off job:
-//   CUOPT_TEST_COREDUMP=1 ulimit -c unlimited ./COREDUMP_SANITY_TEST
-TEST(CoredumpSanity, IntentionalSegfaultWhenEnvSet)
-{
-  if (!coredump_env_enabled()) {
-    GTEST_SKIP() << "Set CUOPT_TEST_COREDUMP=1 to intentionally SIGSEGV for core dump checks.";
-  }
-  std::raise(SIGSEGV);
-}

From cd5cf1f0a8844ffc071b1fc11fca77809d1f79c9 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 16:05:05 -0500
Subject: [PATCH 11/18] revert ctesting addons

---
 ci/run_ctests.sh | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/ci/run_ctests.sh b/ci/run_ctests.sh
index 01508ffc01..bdd5857c06 100755
--- a/ci/run_ctests.sh
+++ b/ci/run_ctests.sh
@@ -25,11 +25,7 @@ shopt -s nullglob
 for gt in "${GTEST_DIR}"/*_TEST; do
     test_name=$(basename "${gt}")
     echo "Running gtest ${test_name}"
-    if ! "${gt}" "$@"; then
-      _g_rc=$?
-      echo "ERROR: gtest ${test_name} failed (exit ${_g_rc}); stopping run_ctests.sh" >&2
-      exit "${_g_rc}"
-    fi
+    "${gt}" "$@"
 done
 shopt -u nullglob
 

From f33d6b43c9f7403400dd15d28f1b18c96fbbaf40 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 16:07:47 -0500
Subject: [PATCH 12/18] revert changes

---
 ci/test_cpp.sh | 13 ++++---------
 1 file changed, 4 insertions(+), 9 deletions(-)

diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index 1caaed4c54..d9d0e36e7c 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -51,19 +51,14 @@ pushd "${RAPIDS_DATASET_ROOT_DIR}"
 ./get_test_data.sh
 popd
 
+EXITCODE=0
+trap "EXITCODE=1" ERR
 set +e
-
 # Run gtests from libcuopt-tests package
 export GTEST_OUTPUT=xml:${RAPIDS_TESTS_DIR}/
 
 rapids-logger "Run gtests"
 timeout 40m ./ci/run_ctests.sh
-EXITCODE=$?
-set -e
-
-if [[ "${EXITCODE}" -ne 0 ]]; then
-  rapids-logger "run_ctests.sh failed (exit ${EXITCODE}); skipping remaining steps"
-fi
 
-rapids-logger "Test script exiting with value: ${EXITCODE}"
-exit "${EXITCODE}"
+rapids-logger "Test script exiting with value: $EXITCODE"
+exit ${EXITCODE}

From f707b553f90cf847b1b992d8599cbecb71958e95 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 16:38:27 -0500
Subject: [PATCH 13/18] refactor

---
 ci/test_cpp.sh                    | 19 +++++++++++++------
 ci/test_cpp_memcheck.sh           |  9 +++------
 ci/test_notebooks.sh              |  9 +++------
 ci/test_python.sh                 |  9 +++------
 ci/test_self_hosted_service.sh    |  9 +++------
 ci/test_skills_assets.sh          |  9 +++------
 ci/test_wheel_cuopt.sh            |  9 +++------
 ci/test_wheel_cuopt_server.sh     |  9 +++------
 ci/{ => utils}/cuopt_coredumps.sh | 10 ++++++++--
 9 files changed, 42 insertions(+), 50 deletions(-)
 rename ci/{ => utils}/cuopt_coredumps.sh (95%)

diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index d9d0e36e7c..ec386f9e6f 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -5,12 +5,9 @@
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 . /opt/conda/etc/profile.d/conda.sh
 
@@ -60,5 +57,15 @@ export GTEST_OUTPUT=xml:${RAPIDS_TESTS_DIR}/
 rapids-logger "Run gtests"
 timeout 40m ./ci/run_ctests.sh
 
+# Optional core-dump path check: no compiled binary — child bash sends itself SIGSEGV.
+# Child exits 139; || true keeps this script running so the EXIT trap can collect cores.
+# For normal CI, leave unset and set CUOPT_CI_COREDUMP_PROBE=1 only when probing artifacts.
+CUOPT_CI_COREDUMP_PROBE=1
+if [[ "${CUOPT_CI_COREDUMP_PROBE:-}" == 1 ]]; then
+  rapids-logger "CUOPT_CI_COREDUMP_PROBE: child bash SIGSEGV (core dump artifact check)"
+  bash -c 'kill -SEGV $$' || true
+  sleep 0.2
+fi
+
 rapids-logger "Test script exiting with value: $EXITCODE"
 exit ${EXITCODE}
diff --git a/ci/test_cpp_memcheck.sh b/ci/test_cpp_memcheck.sh
index d9ddbc7edd..8b61198240 100755
--- a/ci/test_cpp_memcheck.sh
+++ b/ci/test_cpp_memcheck.sh
@@ -10,12 +10,9 @@ fi
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_notebooks.sh b/ci/test_notebooks.sh
index b7897e4032..54bb4d2967 100755
--- a/ci/test_notebooks.sh
+++ b/ci/test_notebooks.sh
@@ -5,12 +5,9 @@
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_python.sh b/ci/test_python.sh
index aec654ad17..831d4dc174 100755
--- a/ci/test_python.sh
+++ b/ci/test_python.sh
@@ -5,12 +5,9 @@
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 . /opt/conda/etc/profile.d/conda.sh
 
diff --git a/ci/test_self_hosted_service.sh b/ci/test_self_hosted_service.sh
index c9b7d509b6..ef0ab14b35 100755
--- a/ci/test_self_hosted_service.sh
+++ b/ci/test_self_hosted_service.sh
@@ -5,12 +5,9 @@
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 source rapids-init-pip
 
diff --git a/ci/test_skills_assets.sh b/ci/test_skills_assets.sh
index ccb5161a11..583044bea0 100755
--- a/ci/test_skills_assets.sh
+++ b/ci/test_skills_assets.sh
@@ -10,12 +10,9 @@
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 # Use rapids-logger in CI; fall back to echo for local testing
 if command -v rapids-logger &>/dev/null; then
diff --git a/ci/test_wheel_cuopt.sh b/ci/test_wheel_cuopt.sh
index 33a5300581..2859b96fe3 100755
--- a/ci/test_wheel_cuopt.sh
+++ b/ci/test_wheel_cuopt.sh
@@ -5,12 +5,9 @@
 
 set -euo pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 # sets up a constraints file for 'pip' and puts its location in an exported variable PIP_EXPORT,
 # so those constraints will affect all future 'pip install' calls
diff --git a/ci/test_wheel_cuopt_server.sh b/ci/test_wheel_cuopt_server.sh
index 19c4bf7c1a..cda880765c 100755
--- a/ci/test_wheel_cuopt_server.sh
+++ b/ci/test_wheel_cuopt_server.sh
@@ -5,12 +5,9 @@
 
 set -eou pipefail
 
-_CUOPT_CI_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-# shellcheck source=ci/cuopt_coredumps.sh
-source "${_CUOPT_CI_DIR}/cuopt_coredumps.sh"
-cuopt_enable_coredumps
-trap 'cuopt_collect_coredumps || true' EXIT
-unset _CUOPT_CI_DIR
+# shellcheck source=ci/utils/cuopt_coredumps.sh
+source "$(dirname "${BASH_SOURCE[0]}")/utils/cuopt_coredumps.sh"
+cuopt_coredumps_ci_setup
 
 source rapids-init-pip
 
diff --git a/ci/cuopt_coredumps.sh b/ci/utils/cuopt_coredumps.sh
similarity index 95%
rename from ci/cuopt_coredumps.sh
rename to ci/utils/cuopt_coredumps.sh
index 44b2e7030a..c8ec2ef84f 100644
--- a/ci/cuopt_coredumps.sh
+++ b/ci/utils/cuopt_coredumps.sh
@@ -17,8 +17,8 @@
 #      no edits here — e.g. test_foo.sh → conda-foo-tests, test_wheel_bar.sh → wheel-bar-tests).
 # Then CUDA / Python / arch / build_type from RAPIDS CI env.
 #
-# Shells: source this file from repo ci/ scripts, then call cuopt_enable_coredumps and trap
-# cuopt_collect_coredumps on EXIT.
+# Test drivers: source ci/utils/cuopt_coredumps.sh from a sibling ci/test_*.sh, then call
+# cuopt_coredumps_ci_setup (enable + EXIT trap).
 
 # Set in cuopt_enable_coredumps; collect reuses when non-empty.
 CUOPT_GDB_CORE_ARTIFACT_DIR=
@@ -201,3 +201,9 @@ cuopt_collect_coredumps() {
     fi
   fi
 }
+
+# Standard CI wiring for ci/test_*.sh: call once after sourcing this file.
+cuopt_coredumps_ci_setup() {
+  cuopt_enable_coredumps
+  trap 'cuopt_collect_coredumps || true' EXIT
+}

From f97a868ea7876225025025715289fbf28e9dddf8 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Mon, 6 Apr 2026 16:41:43 -0500
Subject: [PATCH 14/18] update

---
 ci/run_ctests.sh | 2 --
 1 file changed, 2 deletions(-)

diff --git a/ci/run_ctests.sh b/ci/run_ctests.sh
index bdd5857c06..fc1de8e1b4 100755
--- a/ci/run_ctests.sh
+++ b/ci/run_ctests.sh
@@ -21,13 +21,11 @@ else
     exit 1
 fi
 
-shopt -s nullglob
 for gt in "${GTEST_DIR}"/*_TEST; do
     test_name=$(basename "${gt}")
     echo "Running gtest ${test_name}"
     "${gt}" "$@"
 done
-shopt -u nullglob
 
 # Run C_API_TEST with CPU memory for local solves (excluding time limit tests)
 if [ -x "${GTEST_DIR}/C_API_TEST" ]; then

From d44697472037a3fe5ee364ee8cd9eede4061dec6 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Thu, 9 Apr 2026 10:29:49 -0500
Subject: [PATCH 15/18] update

---
 ci/test_cpp.sh              |  17 +++-
 ci/utils/cuopt_coredumps.sh | 191 +++++++++++++++++++++++++++++-------
 2 files changed, 172 insertions(+), 36 deletions(-)

diff --git a/ci/test_cpp.sh b/ci/test_cpp.sh
index ec386f9e6f..719e26bcb9 100755
--- a/ci/test_cpp.sh
+++ b/ci/test_cpp.sh
@@ -63,8 +63,23 @@ timeout 40m ./ci/run_ctests.sh
 CUOPT_CI_COREDUMP_PROBE=1
 if [[ "${CUOPT_CI_COREDUMP_PROBE:-}" == 1 ]]; then
   rapids-logger "CUOPT_CI_COREDUMP_PROBE: child bash SIGSEGV (core dump artifact check)"
+  # Count core files before the probe.
+  _probe_n_before="$(find "${CUOPT_COREDUMP_DIR:-/dev/null}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
   bash -c 'kill -SEGV $$' || true
-  sleep 0.2
+  # Brief pause so the kernel can finish writing the core.
+  sleep 1
+  # Eagerly collect now so we can verify the probe worked.
+  cuopt_collect_coredumps || true
+  _probe_n_after="$(find "${CUOPT_COREDUMP_DIR:-/dev/null}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
+  if [[ "${_probe_n_after}" -gt "${_probe_n_before}" ]]; then
+    rapids-logger "COREDUMP_PROBE: SUCCESS — $((_probe_n_after - _probe_n_before)) core file(s) collected"
+  else
+    rapids-logger "COREDUMP_PROBE: FAILED — no core file collected for SIGSEGV probe"
+    rapids-logger "  core_pattern=$(cat /proc/sys/kernel/core_pattern 2>/dev/null || echo n/a)"
+    rapids-logger "  ulimit -c=$(ulimit -c)"
+    rapids-logger "  CUOPT_COREDUMP_DIR=${CUOPT_COREDUMP_DIR:-unset}"
+    rapids-logger "  Hint: core_pattern may require a privileged container or --cap-add=SYS_PTRACE"
+  fi
 fi
 
 rapids-logger "Test script exiting with value: $EXITCODE"
diff --git a/ci/utils/cuopt_coredumps.sh b/ci/utils/cuopt_coredumps.sh
index c8ec2ef84f..61de4fc2d9 100644
--- a/ci/utils/cuopt_coredumps.sh
+++ b/ci/utils/cuopt_coredumps.sh
@@ -124,6 +124,9 @@ cuopt_enable_coredumps() {
   CUOPT_GDB_CORE_ARTIFACT_DIR="$(cuopt__gdb_core_artifact_basename)"
   export CUOPT_GDB_CORE_ARTIFACT_DIR
   export CUOPT_COREDUMP_DIR="${base}/${CUOPT_GDB_CORE_ARTIFACT_DIR}"
+  # Record startup time so coredumpctl collection can filter to this session only.
+  export CUOPT_COREDUMP_SINCE
+  CUOPT_COREDUMP_SINCE="$(date '+%Y-%m-%d %H:%M:%S' 2>/dev/null || echo '')"
   mkdir -p "${CUOPT_COREDUMP_DIR}"
 
   local pattern_target="${CUOPT_COREDUMP_DIR}/core.%e.%p.%t"
@@ -132,9 +135,11 @@ cuopt_enable_coredumps() {
   ulimit -c unlimited 2>/dev/null || true
   ulimit -H -c unlimited 2>/dev/null || true
 
-  # When unset, ask the kernel for broad core dump contents (Linux 4.6+; ignored elsewhere).
-  if [[ -z "${COREDUMP_FILTER:-}" ]]; then
-    export COREDUMP_FILTER=0xff
+  # Write the coredump filter to the kernel's per-process file (env var alone has no effect).
+  # 0xff = dump all memory segments (shared, private, huge, DAX — Linux 4.6+).
+  local filter="${COREDUMP_FILTER:-0xff}"
+  if [[ -w /proc/self/coredump_filter ]]; then
+    echo "${filter}" >/proc/self/coredump_filter 2>/dev/null || true
   fi
 
   # Prefer writing cores as files under CUOPT_COREDUMP_DIR (often fails in unprivileged Docker).
@@ -146,21 +151,139 @@ cuopt_enable_coredumps() {
   fi
 
   pattern="$(cat /proc/sys/kernel/core_pattern 2>/dev/null || echo n/a)"
+
+  # Track whether core_pattern points to our directory (file-based) or a pipe/collector.
+  export CUOPT_COREDUMP_PATTERN_IS_PIPE=0
+  if [[ "${pattern}" == \|* ]]; then
+    CUOPT_COREDUMP_PATTERN_IS_PIPE=1
+  fi
+
+  local coredump_filter_val="n/a"
+  if [[ -r /proc/self/coredump_filter ]]; then
+    coredump_filter_val="$(cat /proc/self/coredump_filter 2>/dev/null || echo n/a)"
+  fi
+
+  local _log_msg="Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit=$(ulimit -c) core_pattern=${pattern} coredump_filter=${coredump_filter_val}"
   if declare -F rapids-logger &>/dev/null; then
-    rapids-logger "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit -c=$(ulimit -c) core_pattern=${pattern}"
-    if [[ "${pattern}" == \|* ]]; then
-      rapids-logger "WARNING: core_pattern pipes to a collector (e.g. apport); cores may not appear as files under ${CUOPT_COREDUMP_DIR}. Use a writable core_pattern or a privileged runner if needed."
-    fi
+    rapids-logger "${_log_msg}"
   else
-    echo "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit -c=$(ulimit -c) core_pattern=${pattern}"
-    if [[ "${pattern}" == \|* ]]; then
-      echo "WARNING: core_pattern pipes to a collector; files may not land in ${CUOPT_COREDUMP_DIR}" >&2
+    echo "${_log_msg}"
+  fi
+
+  if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE}" == 1 ]]; then
+    local _pipe_msg="WARNING: core_pattern pipes to a collector — cores will NOT appear as files. Fallback: coredumpctl (systemd-coredump) or /var/crash (apport) will be checked at collection time."
+    if command -v coredumpctl &>/dev/null; then
+      _pipe_msg+=" coredumpctl is available."
+    else
+      _pipe_msg+=" coredumpctl NOT found; if systemd-coredump is the handler, cores may be lost."
+    fi
+    if declare -F rapids-logger &>/dev/null; then
+      rapids-logger "${_pipe_msg}"
+    else
+      echo "WARNING: ${_pipe_msg}" >&2
     fi
   fi
 }
 
+cuopt__log() {
+  if declare -F rapids-logger &>/dev/null; then
+    rapids-logger "$1"
+  else
+    echo "$1"
+  fi
+}
+
+# Copy a single core file into the artifact directory with a sanitized name.
+cuopt__copy_core_to_dest() {
+  local f="$1" dest="$2" label="${3:-}"
+  [[ -f "${f}" && -s "${f}" ]] || return 0
+  local base_name
+  base_name="$(basename "${f}")"
+  if [[ -n "${label}" ]]; then
+    base_name="${label}_${base_name}"
+  fi
+  base_name="${base_name//\//_}"
+  local dest_path="${dest}/${base_name}"
+  if [[ -e "${dest_path}" ]]; then
+    dest_path="${dest}/${base_name}.${RANDOM}"
+  fi
+  cp -a "${f}" "${dest_path}" 2>/dev/null || true
+}
+
+# Collect cores written as files (core_pattern was file-based or we got lucky).
+cuopt__collect_core_files() {
+  local dest="$1"
+  shift
+  local search_dirs=("$@")
+  local f
+  for dir in "${search_dirs[@]}"; do
+    [[ -d "${dir}" ]] || continue
+    while IFS= read -r -d '' f; do
+      [[ -f "${f}" ]] || continue
+      # Skip files already in dest.
+      case "${f}" in
+        "${dest}/"*) continue ;;
+      esac
+      cuopt__copy_core_to_dest "${f}" "${dest}" ""
+    done < <(
+      find "${dir}" \
+        \( -path '*/.git/*' -o -path '*/opt/conda/*' -o -path '*/conda_pkgs/*' -o -path "${dest}/*" \) -prune -o \
+        \( -name 'core' -o -name 'core.*' \) -type f -print0 2>/dev/null
+    )
+  done
+}
+
+# Fallback: extract cores via coredumpctl (systemd-coredump handler).
+cuopt__collect_via_coredumpctl() {
+  local dest="$1"
+  command -v coredumpctl &>/dev/null || return 0
+
+  cuopt__log "Attempting coredumpctl extraction (core_pattern is piped to systemd-coredump)"
+
+  # Build the coredumpctl list command — scope to this session if we have a start time.
+  local -a list_cmd=(coredumpctl list --no-pager --no-legend)
+  if [[ -n "${CUOPT_COREDUMP_SINCE:-}" ]]; then
+    list_cmd+=(--since "${CUOPT_COREDUMP_SINCE}")
+    cuopt__log "  Filtering coredumpctl to cores since ${CUOPT_COREDUMP_SINCE}"
+  fi
+
+  local line pid exe core_path
+  # --no-legend output format: DAY DATE TIME TZ PID UID GID SIG COREFILE EXE...
+  while IFS= read -r line; do
+    # Skip header / empty lines.
+    [[ "${line}" =~ ^[[:space:]]*[A-Z] ]] && continue
+    [[ -z "${line}" ]] && continue
+    # Parse PID (5th field) and EXE (last field).
+    pid="$(echo "${line}" | awk '{print $5}')"
+    exe="$(echo "${line}" | awk '{print $NF}')"
+    [[ -n "${pid}" ]] || continue
+    core_path="${dest}/coredumpctl_${pid}_$(basename "${exe:-unknown}").core"
+    if [[ -e "${core_path}" ]]; then
+      core_path="${core_path}.${RANDOM}"
+    fi
+    coredumpctl dump "${pid}" -o "${core_path}" 2>/dev/null || true
+    if [[ -s "${core_path}" ]]; then
+      cuopt__log "Extracted core for PID ${pid} (${exe}) → ${core_path} ($(du -h "${core_path}" | cut -f1))"
+    else
+      rm -f "${core_path}" 2>/dev/null || true
+    fi
+  done < <("${list_cmd[@]}" 2>/dev/null || true)
+}
+
+# Fallback: collect cores from apport crash reports (/var/crash).
+cuopt__collect_from_apport() {
+  local dest="$1"
+  local crash_dir="/var/crash"
+  [[ -d "${crash_dir}" ]] || return 0
+  local f
+  for f in "${crash_dir}"/*.crash "${crash_dir}"/core.* "${crash_dir}"/core; do
+    [[ -f "${f}" && -s "${f}" ]] || continue
+    cuopt__copy_core_to_dest "${f}" "${dest}" "apport"
+  done
+}
+
 cuopt_collect_coredumps() {
-  local ws base dest n_before n_after f rel dest_name dest_path
+  local ws base dest n_before n_after
   ws="${GITHUB_WORKSPACE:-${PWD}}"
   base="${RAPIDS_ARTIFACTS_DIR:-${ws}/artifacts}"
   if [[ -z "${CUOPT_GDB_CORE_ARTIFACT_DIR:-}" ]]; then
@@ -171,33 +294,31 @@ cuopt_collect_coredumps() {
 
   n_before="$(find "${dest}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
 
-  while IFS= read -r -d '' f; do
-    [[ -f "${f}" ]] || continue
-    case "${f}" in
-      "${dest}/"*) continue ;;
-    esac
-    rel="${f#"${ws}"/}"
-    if [[ "${rel}" == "${f}" ]]; then
-      rel="$(basename "${f}")"
-    fi
-    dest_name="${rel//\//_}"
-    dest_path="${dest}/${dest_name}"
-    if [[ -e "${dest_path}" ]]; then
-      dest_path="${dest}/${dest_name}.${RANDOM}"
-    fi
-    cp -a "${f}" "${dest_path}" 2>/dev/null || true
-  done < <(
-    find "${ws}" \
-      \( -path '*/.git/*' -o -path '*/opt/conda/*' -o -path '*/conda_pkgs/*' -o -path "${dest}/*" \) -prune -o \
-      \( -name 'core' -o -name 'core.*' \) -type f -print0 2>/dev/null
-  )
+  # 1) Search for core files in workspace + common system locations.
+  cuopt__collect_core_files "${dest}" \
+    "${ws}" "/tmp" "/var/lib/systemd/coredump" "/var/crash"
+
+  # 2) If core_pattern pipes to a collector, try extracting via coredumpctl / apport.
+  if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE:-0}" == 1 ]]; then
+    cuopt__collect_via_coredumpctl "${dest}"
+    cuopt__collect_from_apport "${dest}"
+  fi
 
   n_after="$(find "${dest}" -type f 2>/dev/null | wc -l | tr -d '[:space:]')"
   if [[ "${n_after}" -gt "${n_before}" ]]; then
-    if declare -F rapids-logger &>/dev/null; then
-      rapids-logger "Wrote $((n_after - n_before)) core file(s) into ${dest} (${n_after} total)"
-    else
-      echo "cuOpt coredumps: ${n_after} file(s) in ${dest}"
+    cuopt__log "Collected $((n_after - n_before)) core file(s) into ${dest} (${n_after} total)"
+    ls -lh "${dest}"/ 2>/dev/null || true
+  else
+    cuopt__log "WARNING: No core files found. Cores may have been discarded by the system collector."
+    cuopt__log "  core_pattern=$(cat /proc/sys/kernel/core_pattern 2>/dev/null || echo n/a)"
+    cuopt__log "  Searched: ${ws} /tmp /var/lib/systemd/coredump /var/crash"
+    if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE:-0}" == 1 ]]; then
+      if command -v coredumpctl &>/dev/null; then
+        cuopt__log "  coredumpctl list output:"
+        coredumpctl list --no-pager 2>/dev/null || true
+      else
+        cuopt__log "  coredumpctl not available; cannot extract from systemd-coredump"
+      fi
     fi
   fi
 }

From 5c34d6b04a65296c305bab2d2ad57cdd8a179378 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Thu, 9 Apr 2026 10:31:07 -0500
Subject: [PATCH 16/18] fix

---
 ci/utils/cuopt_coredumps.sh | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/ci/utils/cuopt_coredumps.sh b/ci/utils/cuopt_coredumps.sh
index 61de4fc2d9..b76b06f879 100644
--- a/ci/utils/cuopt_coredumps.sh
+++ b/ci/utils/cuopt_coredumps.sh
@@ -163,7 +163,8 @@ cuopt_enable_coredumps() {
     coredump_filter_val="$(cat /proc/self/coredump_filter 2>/dev/null || echo n/a)"
   fi
 
-  local _log_msg="Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit=$(ulimit -c) core_pattern=${pattern} coredump_filter=${coredump_filter_val}"
+  local _log_msg
+  _log_msg="Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit=$(ulimit -c) core_pattern=${pattern} coredump_filter=${coredump_filter_val}"
   if declare -F rapids-logger &>/dev/null; then
     rapids-logger "${_log_msg}"
   else

From 3eb48b9319f9d3e7af3f9aa6ad97a635148c0764 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Thu, 9 Apr 2026 10:40:24 -0500
Subject: [PATCH 17/18] remove redundant items

---
 ci/utils/cuopt_coredumps.sh | 42 ++++++++++++++++---------------------
 1 file changed, 18 insertions(+), 24 deletions(-)

diff --git a/ci/utils/cuopt_coredumps.sh b/ci/utils/cuopt_coredumps.sh
index b76b06f879..5e69b0781c 100644
--- a/ci/utils/cuopt_coredumps.sh
+++ b/ci/utils/cuopt_coredumps.sh
@@ -115,6 +115,14 @@ cuopt__gdb_core_artifact_basename() {
   echo "cuopt-gdb-cores_${job}_cuda${cuda_ver}_py${py_ver}_${arch_}_${bt}"
 }
 
+cuopt__log() {
+  if declare -F rapids-logger &>/dev/null; then
+    rapids-logger "$1"
+  else
+    echo "$1"
+  fi
+}
+
 cuopt_enable_coredumps() {
   local ws base pattern
   ws="${GITHUB_WORKSPACE:-${PWD}}"
@@ -163,13 +171,7 @@ cuopt_enable_coredumps() {
     coredump_filter_val="$(cat /proc/self/coredump_filter 2>/dev/null || echo n/a)"
   fi
 
-  local _log_msg
-  _log_msg="Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit=$(ulimit -c) core_pattern=${pattern} coredump_filter=${coredump_filter_val}"
-  if declare -F rapids-logger &>/dev/null; then
-    rapids-logger "${_log_msg}"
-  else
-    echo "${_log_msg}"
-  fi
+  cuopt__log "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit=$(ulimit -c) core_pattern=${pattern} coredump_filter=${coredump_filter_val}"
 
   if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE}" == 1 ]]; then
     local _pipe_msg="WARNING: core_pattern pipes to a collector — cores will NOT appear as files. Fallback: coredumpctl (systemd-coredump) or /var/crash (apport) will be checked at collection time."
@@ -178,19 +180,7 @@ cuopt_enable_coredumps() {
     else
       _pipe_msg+=" coredumpctl NOT found; if systemd-coredump is the handler, cores may be lost."
     fi
-    if declare -F rapids-logger &>/dev/null; then
-      rapids-logger "${_pipe_msg}"
-    else
-      echo "WARNING: ${_pipe_msg}" >&2
-    fi
-  fi
-}
-
-cuopt__log() {
-  if declare -F rapids-logger &>/dev/null; then
-    rapids-logger "$1"
-  else
-    echo "$1"
+    cuopt__log "${_pipe_msg}"
   fi
 }
 
@@ -258,9 +248,13 @@ cuopt__collect_via_coredumpctl() {
     pid="$(echo "${line}" | awk '{print $5}')"
     exe="$(echo "${line}" | awk '{print $NF}')"
     [[ -n "${pid}" ]] || continue
-    core_path="${dest}/coredumpctl_${pid}_$(basename "${exe:-unknown}").core"
+    local exe_base
+    exe_base="$(basename "${exe:-unknown}")"
+    core_path="${dest}/coredumpctl_${pid}_${exe_base}.core"
+    # Skip if this PID was already extracted (e.g. by a prior probe collection).
     if [[ -e "${core_path}" ]]; then
-      core_path="${core_path}.${RANDOM}"
+      cuopt__log "  Skipping PID ${pid} (${exe_base}) — already extracted"
+      continue
     fi
     coredumpctl dump "${pid}" -o "${core_path}" 2>/dev/null || true
     if [[ -s "${core_path}" ]]; then
@@ -297,7 +291,7 @@ cuopt_collect_coredumps() {
 
   # 1) Search for core files in workspace + common system locations.
   cuopt__collect_core_files "${dest}" \
-    "${ws}" "/tmp" "/var/lib/systemd/coredump" "/var/crash"
+    "${ws}" "/tmp" "/var/lib/systemd/coredump"
 
   # 2) If core_pattern pipes to a collector, try extracting via coredumpctl / apport.
   if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE:-0}" == 1 ]]; then
@@ -312,7 +306,7 @@ cuopt_collect_coredumps() {
   else
     cuopt__log "WARNING: No core files found. Cores may have been discarded by the system collector."
     cuopt__log "  core_pattern=$(cat /proc/sys/kernel/core_pattern 2>/dev/null || echo n/a)"
-    cuopt__log "  Searched: ${ws} /tmp /var/lib/systemd/coredump /var/crash"
+    cuopt__log "  Searched: ${ws} /tmp /var/lib/systemd/coredump (+ /var/crash if piped)"
     if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE:-0}" == 1 ]]; then
       if command -v coredumpctl &>/dev/null; then
         cuopt__log "  coredumpctl list output:"

From 367ec36b273f293511259f40750efb5d182f24f6 Mon Sep 17 00:00:00 2001
From: Ramakrishna Prabhu <ramakrishnap@nvidia.com>
Date: Thu, 9 Apr 2026 12:05:28 -0500
Subject: [PATCH 18/18] hijack apport pipe handler to capture core dumps in
 unprivileged containers

When core_pattern pipes to apport (common in CI), apport silently
discards cores from non-packaged binaries. Replace the handler with a
forwarder script that reads the core from stdin and writes it to the
artifact directory. Falls back gracefully if the handler is read-only.
---
 ci/utils/cuopt_coredumps.sh | 72 ++++++++++++++++++++++++++++++++++---
 1 file changed, 68 insertions(+), 4 deletions(-)

diff --git a/ci/utils/cuopt_coredumps.sh b/ci/utils/cuopt_coredumps.sh
index 5e69b0781c..b0a85d5918 100644
--- a/ci/utils/cuopt_coredumps.sh
+++ b/ci/utils/cuopt_coredumps.sh
@@ -123,6 +123,61 @@ cuopt__log() {
   fi
 }
 
+# When core_pattern pipes to a handler (apport/systemd-coredump), replace the handler
+# binary with a forwarder script that reads the core from stdin and writes it to disk.
+# The kernel invokes: |/path/to/handler -p%p -s%s ... -- %E
+# Our replacement reads stdin (the raw core) and writes it using the -p (PID) argument.
+cuopt__hijack_pipe_handler() {
+  local pattern="$1" dest="$2"
+  # Extract the handler binary path (first token after the leading '|').
+  local handler
+  handler="$(echo "${pattern}" | sed 's/^|//; s/ .*//')"
+  [[ -n "${handler}" && -f "${handler}" ]] || return 0
+
+  # Back up the original handler (only once).
+  local backup="${handler}.cuopt_orig"
+  if [[ ! -f "${backup}" ]]; then
+    cp -a "${handler}" "${backup}" 2>/dev/null || {
+      cuopt__log "WARNING: cannot back up ${handler} — hijack skipped (read-only?)"
+      return 0
+    }
+  fi
+
+  # Write a forwarder script that saves stdin (core dump) to the artifact dir.
+  # The kernel passes flags like -p PID; we parse -p to name the file.
+  cat > "${handler}" <<'FORWARDER_EOF'
+#!/bin/sh
+# cuOpt core-dump forwarder — replaces apport/systemd-coredump handler.
+# Reads raw core dump from stdin, writes to CUOPT_COREDUMP_DIR.
+PID="unknown"
+EXE="unknown"
+while [ $# -gt 0 ]; do
+  case "$1" in
+    -p) shift; PID="$1" ;;
+    -p*) PID="${1#-p}" ;;
+    --) shift; EXE="$(echo "$*" | tr '/' '_')" ; break ;;
+  esac
+  shift
+done
+FORWARDER_EOF
+  # Append the dest directory (expanded now, not at runtime).
+  cat >> "${handler}" <<FORWARDER_DEST
+DEST="${dest}"
+FORWARDER_DEST
+  cat >> "${handler}" <<'FORWARDER_BODY'
+mkdir -p "${DEST}" 2>/dev/null
+CORE_FILE="${DEST}/core.${EXE}.${PID}"
+cat > "${CORE_FILE}"
+if [ -s "${CORE_FILE}" ]; then
+  echo "cuopt-forwarder: saved core for PID ${PID} (${EXE}) → ${CORE_FILE}" >&2
+else
+  rm -f "${CORE_FILE}" 2>/dev/null
+fi
+FORWARDER_BODY
+  chmod +x "${handler}" 2>/dev/null || true
+  cuopt__log "Hijacked pipe handler ${handler} → core forwarder (dest=${dest})"
+}
+
 cuopt_enable_coredumps() {
   local ws base pattern
   ws="${GITHUB_WORKSPACE:-${PWD}}"
@@ -164,6 +219,10 @@ cuopt_enable_coredumps() {
   export CUOPT_COREDUMP_PATTERN_IS_PIPE=0
   if [[ "${pattern}" == \|* ]]; then
     CUOPT_COREDUMP_PATTERN_IS_PIPE=1
+    # Attempt to hijack the pipe handler (e.g. apport) with a forwarder that saves cores
+    # as files. The kernel pipes the core dump on stdin to the handler binary; if we replace
+    # it with our own script, the core lands in CUOPT_COREDUMP_DIR.
+    cuopt__hijack_pipe_handler "${pattern}" "${CUOPT_COREDUMP_DIR}"
   fi
 
   local coredump_filter_val="n/a"
@@ -174,11 +233,16 @@ cuopt_enable_coredumps() {
   cuopt__log "Core dumps: dir=${CUOPT_COREDUMP_DIR} ulimit=$(ulimit -c) core_pattern=${pattern} coredump_filter=${coredump_filter_val}"
 
   if [[ "${CUOPT_COREDUMP_PATTERN_IS_PIPE}" == 1 ]]; then
-    local _pipe_msg="WARNING: core_pattern pipes to a collector — cores will NOT appear as files. Fallback: coredumpctl (systemd-coredump) or /var/crash (apport) will be checked at collection time."
-    if command -v coredumpctl &>/dev/null; then
-      _pipe_msg+=" coredumpctl is available."
+    local _pipe_msg="core_pattern pipes to a collector."
+    if [[ -f "$(echo "${pattern}" | sed 's/^|//; s/ .*//' ).cuopt_orig" ]]; then
+      _pipe_msg+=" Handler hijacked with core forwarder — cores should land in ${CUOPT_COREDUMP_DIR}."
     else
-      _pipe_msg+=" coredumpctl NOT found; if systemd-coredump is the handler, cores may be lost."
+      _pipe_msg+=" Handler hijack failed. Fallback: coredumpctl / /var/crash at collection time."
+      if command -v coredumpctl &>/dev/null; then
+        _pipe_msg+=" coredumpctl is available."
+      else
+        _pipe_msg+=" coredumpctl NOT found; cores may be lost."
+      fi
     fi
     cuopt__log "${_pipe_msg}"
   fi