test case 2646_1 failure depends on build options

Steps to reproduce

for mode in Debug ReWithDebInfo; do
cmake CC=clang CXX=clang -DENABLE_LTDL=ON -DCMAKE_BUILD_TYPE=${mode} -DCMAKE_INSTALL_PREFIX=/tmp/foo -B build -S .
cmake --build build
cmake --install build
env PATH=${PREFIX}/bin:${PATH} C_INCLUDE_PATH=${PREFIX}/include \
  LD_LIBRARY_PATH=${PREFIX}/lib LIBRARY_PATH=${PREFIX}/lib \
  PYTHONPATH=${PREFIX}/lib/graphviz/python3 \
  TCLLIBPATH=${PREFIX}/lib/graphviz/tcl \
  PKG_CONFIG_PATH=${PREFIX}/lib/pkgconfig \
  graphviz_ROOT=${PREFIX} build_system=cmake \
  python3 -m pytest --durations=0 --durations-min=1.0 tests/test_regression.py::test_2646_1
done

Expected Behavior

Both tests pass.

Actual Behavior

Test 2646_1 fails when CMAKE_BUILD_TYPE=Debug

OS Version

Linux, Ubuntu 24.04.3 LTS Ubuntu clang version 22.0.0 (++20260105081943+212527c00ba6-1exp120260105082109.1379)

Graphviz Version

dot - graphviz version 14.1.3~dev.20260207.0611 (20260207.0611) Current HEAD: commit d49debc4

Additional info

I note that in debugging mode stack frames seem to all be 256 bytes. In RelWithDebInfo some other frames are inlined, inter_tree_edge_search frames are 44 bytes at the recursive call.