From ba9e37c40e70521255cca4f8d1a44426dfffe0ea Mon Sep 17 00:00:00 2001
From: Pierre Raybaut <1311787+PierreRaybaut@users.noreply.github.com>
Date: Tue, 20 Oct 2026 15:20:42 +0200
Subject: [PATCH] test(ci): report crashes of the test process

A test process crash left no Python traceback in the CI logs: the DataLab
application context redirected faulthandler to a log file kept on the runner,
then disabled it, including pytest's own handler, for all subsequent tests.

Tests now keep pytest's faulthandler, so that crash tracebacks are reported in
the test output. The PyQt5 workflow also keeps the core dump of a crashed test
process and prints its native backtrace.

Assisted-by: Claude Opus 5.5
---
 .github/workflows/test_pyqt5.yml | 22 +++++++++++++++++++++-
 datalab/tests/conftest.py        |  3 +++
 2 files changed, 24 insertions(+), 1 deletion(-)

diff --git a/.github/workflows/test_pyqt5.yml b/.github/workflows/test_pyqt5.yml
index cfb5a2d79..725a19119 100644
--- a/.github/workflows/test_pyqt5.yml
+++ b/.github/workflows/test_pyqt5.yml
@@ -117,7 +117,27 @@ jobs:
     - name: Lint with Ruff
       run: ruff check --output-format=github datalab
     - name: Test with pytest
-      run: pytest -v --tb=long
+      run: |
+        # Keep the core dump of a crashed test process, for the backtrace step below
+        sudo mkdir -p /tmp/cores && sudo chmod 1777 /tmp/cores || true
+        sudo sysctl -q -w kernel.core_pattern=/tmp/cores/core.%p || true
+        ulimit -c unlimited || true
+        pytest -v --tb=long
+    - name: Native backtrace of crashed test process
+      if: failure()
+      run: |
+        shopt -s nullglob
+        cores=(/tmp/cores/core.*)
+        if [ ${#cores[@]} -eq 0 ]; then
+          echo "No core dump found"
+          exit 0
+        fi
+        sudo apt-get install -y gdb
+        python_exe="$(python -c 'import sys; print(sys.executable)')"
+        for core in "${cores[@]}"; do
+          echo "===== Backtrace of $core"
+          gdb -batch -ex "thread apply all bt 50" "$python_exe" "$core"
+        done
 
   build_latest:
     if: ${{ github.event_name == 'schedule' || (github.event_name == 'workflow_dispatch' && (github.event.inputs.job_to_run == 'all' || github.event.inputs.job_to_run == 'build_latest')) }}
diff --git a/datalab/tests/conftest.py b/datalab/tests/conftest.py
index baf39f9aa..065c1dd90 100644
--- a/datalab/tests/conftest.py
+++ b/datalab/tests/conftest.py
@@ -47,6 +47,9 @@ def reset_datalab_configuration():
     ensure_initialized(load_user_config=False)
     reset_to_defaults()
     Conf.rpc_server_enabled.set(False)
+    # Keep pytest's faulthandler, which reports crashes in the test output: the
+    # application context would redirect it to a log file, then disable it
+    Conf.faulthandler_enabled.set(False)
     try:
         yield
     finally: