in order to debug this, I started gdb set a breakpoint in init_module_scitbx_linalg_ext
then a catch throw and I end up with this backtrace Catchpoint 2 (exception thrown), 0x00007ffff70a90a1 in __cxxabiv1::__cxa_throw (obj=0xb542e0, tinfo=0x7ffff72d8200 <typeinfo for boost::python::error_already_set>, dest=0x7ffff72c1290 <boost::python::error_already_set::~error_already_set()>) at ../../../../src/libstdc++-v3/libsupc++/eh_throw.cc:81 81 ../../../../src/libstdc++-v3/libsupc++/eh_throw.cc: Le dossier n'est pas vide. (gdb) bt #0 0x00007ffff70a90a1 in __cxxabiv1::__cxa_throw (obj=0xb542e0, tinfo=0x7ffff72d8200 <typeinfo for boost::python::error_already_set>, dest=0x7ffff72c1290 <boost::python::error_already_set::~error_already_set()>) at ../../../../src/libstdc++-v3/libsupc++/eh_throw.cc:81 #1 0x00007ffff72ad089 in boost::python::throw_error_already_set () at libs/python/src/errors.cpp:61 #2 0x00007ffff72b6f05 in boost::python::objects::(anonymous namespace)::new_enum_type (doc=0x0, name=0x7ffff743ddf9 "bidiagonal_matrix_kind") at libs/python/src/object/enum.cpp:169 #3 boost::python::objects::enum_base::enum_base (this=this@entry=0x7fffffffcee0, name=name@entry=0x7ffff743ddf9 "bidiagonal_matrix_kind", to_python=to_python@entry=0x7ffff741f720 <boost::python::enum_<scitbx::matrix::svd::bidiagonal_kind>::to_python(void const*)>, convertible=convertible@entry=0x7ffff7422e50 <boost::python::enum_<scitbx::matrix::svd::bidiagonal_kind>::convertible_from_python(_object*)>, construct=construct@entry=0x7ffff741fb60 <boost::python::enum_<scitbx::matrix::svd::bidiagonal_kind>::construct(_object*, boost::python::converter::rvalue_from_python_stage1_data*)>, id=..., doc=0x0) at libs/python/src/object/enum.cpp:204 #4 0x00007ffff74203cb in boost::python::enum_<scitbx::matrix::svd::bidiagonal_kind>::enum_ (this=0x7fffffffcee0, name=0x7ffff743ddf9 "bidiagonal_matrix_kind", doc=0x0) at /usr/include/boost/python/enum.hpp:45 #5 0x00007ffff7428330 in scitbx::matrix::boost_python::bidiagonal_matrix_svd_decomposition_wrapper<double>::wrap (name=name@entry=0x7ffff743dbd0 "svd_decomposition_of_bidiagonal_matrix") at ./scitbx/linalg/boost_python/svd.cpp:19 #6 0x00007ffff741f6b0 in scitbx::matrix::boost_python::wrap_svd () at ./scitbx/linalg/boost_python/svd.cpp:66 #7 0x00007ffff73f8aa3 in scitbx::matrix::boost_python::(anonymous namespace)::init_module () at ./scitbx/linalg/boost_python/linalg_ext.cpp:19 #8 0x00007ffff72c13e3 in boost::function0<void>::operator() (this=0x7fffffffd2b0) at ./boost/function/function_template.hpp:763 #9 boost::python::handle_exception_impl (f=...) at libs/python/src/errors.cpp:25 #10 0x00007ffff72c1b69 in boost::python::handle_exception<void (*)()> (f=<optimized out>) at ./boost/function/function_template.hpp:635 #11 boost::python::detail::(anonymous namespace)::init_module_in_scope (init_function=0x7ffff73f8ac0 <init_module_scitbx_linalg_ext()>, m=<module at remote 0x7ffff74ff950>) at libs/python/src/module.cpp:24 #12 boost::python::detail::init_module (moduledef=..., init_function=0x7ffff73f8ac0 <init_module_scitbx_linalg_ext()>) at libs/python/src/module.cpp:43 not crystal clear to me :)