Dear ROOT,
I was running some piece of code on lxplus w/o difficulty and suddenly since 9th of July i encounter a crash. I took me some time to understand that on that day the root version was upgraded. The crash is seen when using pickle to read /afs/cern.ch/user/a/aumarten/public/test2/0.MC (created with the same root installation also using pickle). I copya simple example where I reproduced this error below. Is there any fix that I can apply to that issue ?
thanks,
Aurélien
*ROOT Version:* 6.40.02
*Platform:* Built for linuxx8664gcc on Jun 20 2026, 00:00:00
*Compiler:* g++ (GCC) 11.5.0 20240719 (Red Hat 11.5.0-14) std201703
\--
Python 3.9.25 (main, Apr 17 2026, 00:00:00)
\[GCC 11.5.0 20240719 (Red Hat 11.5.0-14)\] on linux
Type "help", "copyright", "credits" or "license" for more information.
> > > import pickle
> > > abspath='/afs/cern.ch/user/a/aumarten/public/test2/0.MC'
> > > fp=open(abspath, 'rb')
> > > fp
> > > <\_io.BufferedReader name='/eos/home-a/aumarten/epol/test2/0.MC'>
> > > pickle.load(fp)
> > > \*\*\* Break \*\*\* segmentation violation
# ===========================================================
There was a crash.
This is the entire stack trace of all threads:
# #0 0x00007fad546da48a in wait4 () from /lib64/libc.so.6
#1 0x00007fad5464f4b3 in do_system () from /lib64/libc.so.6
#2 0x00007fad538b9bbb in TUnixSystem::StackTrace() () from /usr/lib64/root/libCore.so.6.40
#3 0x00007fad541835e3 in (anonymous namespace)::TExceptionHandlerImp::HandleException(int) \[clone .lto_priv.0\] () from
/usr/lib64/root/libCPyCppyy.so.6.40
#4 0x00007fad538bbd39 in TUnixSystem::DispatchSignals(ESignals) () from /usr/lib64/root/libCore.so.6.40
#5
#6 0x00007fad5417616f in CPyCppyy::CreateScopeProxy(std::\__cxx11::basic_string<char, std::char_traits, std::allocator > const&, \_object\*,
unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#7 0x00007fad5417865d in CPyCppyy::CreateScopeProxy(unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#8 0x00007fad541786ca in CPyCppyy::BindCppObjectNoCast(void\*, unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#9 0x00007fad5411fcfe in CPyCppyy::Instance_FromVoidPtr(void\*, std::\__cxx11::basic_string<char, std::char_traits, std::allocator >
const&, bool) () from /usr/lib64/root/libCPyCppyy.so.6.40
#10 0x00007fad543a91b7 in PyROOT::CPPInstanceExpand(\_object\*, \_object\*) () from
/usr/lib64/python3.9/site-packages/ROOT/libROOTPythonizations.cpython-39-x86_64-linux-gnu.so
#11 0x00007fad54b524e8 in cfunction_call () from /lib64/libpython3.9.so.1.0
#12 0x00007fad54b5090f in \_PyObject_Call () from /lib64/libpython3.9.so.1.0
#13 0x00007fad5482e2d8 in load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#14 0x00007fad54835587 in \_pickle_load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#15 0x00007fad54b38d8f in cfunction_vectorcall_FASTCALL_KEYWORDS () from /lib64/libpython3.9.so.1.0
#16 0x00007fad54b35a0b in \_PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#17 0x00007fad54b2f219 in \_PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#18 0x00007fad54b2ee85 in \_PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#19 0x00007fad54be39a7 in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#20 0x00007fad54c11474 in run_eval_code_obj () from /lib64/libpython3.9.so.1.0
#21 0x00007fad54c0d56b in run_mod () from /lib64/libpython3.9.so.1.0
#22 0x00007fad54b16c30 in PyRun_InteractiveOneObjectEx () from /lib64/libpython3.9.so.1.0
#23 0x00007fad54b1798b in PyRun_InteractiveLoopFlags () from /lib64/libpython3.9.so.1.0
#24 0x00007fad54a9760f in PyRun_AnyFileExFlags.cold () from /lib64/libpython3.9.so.1.0
#25 0x00007fad54a946c8 in Py_RunMain.cold () from /lib64/libpython3.9.so.1.0
#26 0x00007fad54bd641d in Py_BytesMain () from /lib64/libpython3.9.so.1.0
#27 0x00007fad5462a610 in \__libc_start_call_main () from /lib64/libc.so.6
#28 0x00007fad5462a6c0 in \__libc_start_main_impl () from /lib64/libc.so.6
#29 0x000055fea1942095 in \_start ()
# The lines below might hint at the cause of the crash. If you see question
marks as part of the stack trace, try to recompile with debugging information
enabled and export CLING_DEBUG=1 environment variable before running.
You may get help by asking at the ROOT forum
# #6 0x00007fad5417616f in CPyCppyy::CreateScopeProxy(std::\__cxx11::basic_string<char, std::char_traits, std::allocator > const&, \_object\*,
unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#7 0x00007fad5417865d in CPyCppyy::CreateScopeProxy(unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#8 0x00007fad541786ca in CPyCppyy::BindCppObjectNoCast(void\*, unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#9 0x00007fad5411fcfe in CPyCppyy::Instance_FromVoidPtr(void\*, std::\__cxx11::basic_string<char, std::char_traits, std::allocator >
const&, bool) () from /usr/lib64/root/libCPyCppyy.so.6.40
#10 0x00007fad543a91b7 in PyROOT::CPPInstanceExpand(\_object\*, \_object\*) () from
/usr/lib64/python3.9/site-packages/ROOT/libROOTPythonizations.cpython-39-x86_64-linux-gnu.so
#11 0x00007fad54b524e8 in cfunction_call () from /lib64/libpython3.9.so.1.0
#12 0x00007fad54b5090f in \_PyObject_Call () from /lib64/libpython3.9.so.1.0
#13 0x00007fad5482e2d8 in load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#14 0x00007fad54835587 in \_pickle_load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#15 0x00007fad54b38d8f in cfunction_vectorcall_FASTCALL_KEYWORDS () from /lib64/libpython3.9.so.1.0
#16 0x00007fad54b35a0b in \_PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#17 0x00007fad54b2f219 in \_PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#18 0x00007fad54b2ee85 in \_PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#19 0x00007fad54be39a7 in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#20 0x00007fad54c11474 in run_eval_code_obj () from /lib64/libpython3.9.so.1.0
#21 0x00007fad54c0d56b in run_mod () from /lib64/libpython3.9.so.1.0
#22 0x00007fad54b16c30 in PyRun_InteractiveOneObjectEx () from /lib64/libpython3.9.so.1.0
#23 0x00007fad54b1798b in PyRun_InteractiveLoopFlags () from /lib64/libpython3.9.so.1.0
#24 0x00007fad54a9760f in PyRun_AnyFileExFlags.cold () from /lib64/libpython3.9.so.1.0
#25 0x00007fad54a946c8 in Py_RunMain.cold () from /lib64/libpython3.9.so.1.0
#26 0x00007fad54bd641d in Py_BytesMain () from /lib64/libpython3.9.so.1.0
#27 0x00007fad5462a610 in \__libc_start_call_main () from /lib64/libc.so.6
#28 0x00007fad5462a6c0 in \__libc_start_main_impl () from /lib64/libc.so.6
#29 0x000055fea1942095 in \_start ()
\*\*\* Break \*\*\* segmentation violation
# ===========================================================
There was a crash.
This is the entire stack trace of all threads:
# #0 0x00007fad546da48a in wait4 () from /lib64/libc.so.6
#1 0x00007fad5464f4b3 in do_system () from /lib64/libc.so.6
#2 0x00007fad538b9bbb in TUnixSystem::StackTrace() () from /usr/lib64/root/libCore.so.6.40
#3 0x00007fad54183477 in (anonymous namespace)::TExceptionHandlerImp::HandleException(int) \[clone .lto_priv.0\] () from
/usr/lib64/root/libCPyCppyy.so.6.40
#4 0x00007fad538bbd39 in TUnixSystem::DispatchSignals(ESignals) () from /usr/lib64/root/libCore.so.6.40
#5
#6 0x00007fad5417616f in CPyCppyy::CreateScopeProxy(std::\__cxx11::basic_string<char, std::char_traits, std::allocator > const&, \_object\*,
unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#7 0x00007fad5417865d in CPyCppyy::CreateScopeProxy(unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#8 0x00007fad541786ca in CPyCppyy::BindCppObjectNoCast(void\*, unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#9 0x00007fad5411fcfe in CPyCppyy::Instance_FromVoidPtr(void\*, std::\__cxx11::basic_string<char, std::char_traits, std::allocator >
const&, bool) () from /usr/lib64/root/libCPyCppyy.so.6.40
#10 0x00007fad543a91b7 in PyROOT::CPPInstanceExpand(\_object\*, \_object\*) () from
/usr/lib64/python3.9/site-packages/ROOT/libROOTPythonizations.cpython-39-x86_64-linux-gnu.so
#11 0x00007fad54b524e8 in cfunction_call () from /lib64/libpython3.9.so.1.0
#12 0x00007fad54b5090f in \_PyObject_Call () from /lib64/libpython3.9.so.1.0
#13 0x00007fad5482e2d8 in load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#14 0x00007fad54835587 in \_pickle_load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#15 0x00007fad54b38d8f in cfunction_vectorcall_FASTCALL_KEYWORDS () from /lib64/libpython3.9.so.1.0
#16 0x00007fad54b35a0b in \_PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#17 0x00007fad54b2f219 in \_PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#18 0x00007fad54b2ee85 in \_PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#19 0x00007fad54be39a7 in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#20 0x00007fad54c11474 in run_eval_code_obj () from /lib64/libpython3.9.so.1.0
#21 0x00007fad54c0d56b in run_mod () from /lib64/libpython3.9.so.1.0
#22 0x00007fad54b16c30 in PyRun_InteractiveOneObjectEx () from /lib64/libpython3.9.so.1.0
#23 0x00007fad54b1798b in PyRun_InteractiveLoopFlags () from /lib64/libpython3.9.so.1.0
#24 0x00007fad54a9760f in PyRun_AnyFileExFlags.cold () from /lib64/libpython3.9.so.1.0
#25 0x00007fad54a946c8 in Py_RunMain.cold () from /lib64/libpython3.9.so.1.0
#26 0x00007fad54bd641d in Py_BytesMain () from /lib64/libpython3.9.so.1.0
#27 0x00007fad5462a610 in \__libc_start_call_main () from /lib64/libc.so.6
#28 0x00007fad5462a6c0 in \__libc_start_main_impl () from /lib64/libc.so.6
#29 0x000055fea1942095 in \_start ()
# The lines below might hint at the cause of the crash. If you see question
# #6 0x00007fad5417616f in CPyCppyy::CreateScopeProxy(std::\__cxx11::basic_string<char, std::char_traits, std::allocator > const&, \_object\*,
unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#7 0x00007fad5417865d in CPyCppyy::CreateScopeProxy(unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#8 0x00007fad541786ca in CPyCppyy::BindCppObjectNoCast(void\*, unsigned long, unsigned int) () from /usr/lib64/root/libCPyCppyy.so.6.40
#9 0x00007fad5411fcfe in CPyCppyy::Instance_FromVoidPtr(void\*, std::\__cxx11::basic_string<char, std::char_traits, std::allocator >
const&, bool) () from /usr/lib64/root/libCPyCppyy.so.6.40
#10 0x00007fad543a91b7 in PyROOT::CPPInstanceExpand(\_object\*, \_object\*) () from
/usr/lib64/python3.9/site-packages/ROOT/libROOTPythonizations.cpython-39-x86_64-linux-gnu.so
#11 0x00007fad54b524e8 in cfunction_call () from /lib64/libpython3.9.so.1.0
#12 0x00007fad54b5090f in \_PyObject_Call () from /lib64/libpython3.9.so.1.0
#13 0x00007fad5482e2d8 in load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#14 0x00007fad54835587 in \_pickle_load () from /usr/lib64/python3.9/lib-dynload/\_pickle.cpython-39-x86_64-linux-gnu.so
#15 0x00007fad54b38d8f in cfunction_vectorcall_FASTCALL_KEYWORDS () from /lib64/libpython3.9.so.1.0
#16 0x00007fad54b35a0b in \_PyEval_EvalFrameDefault () from /lib64/libpython3.9.so.1.0
#17 0x00007fad54b2f219 in \_PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#18 0x00007fad54b2ee85 in \_PyEval_EvalCodeWithName () from /lib64/libpython3.9.so.1.0
#19 0x00007fad54be39a7 in PyEval_EvalCode () from /lib64/libpython3.9.so.1.0
#20 0x00007fad54c11474 in run_eval_code_obj () from /lib64/libpython3.9.so.1.0
#21 0x00007fad54c0d56b in run_mod () from /lib64/libpython3.9.so.1.0
#22 0x00007fad54b16c30 in PyRun_InteractiveOneObjectEx () from /lib64/libpython3.9.so.1.0
#23 0x00007fad54b1798b in PyRun_InteractiveLoopFlags () from /lib64/libpython3.9.so.1.0
#24 0x00007fad54a9760f in PyRun_AnyFileExFlags.cold () from /lib64/libpython3.9.so.1.0
#25 0x00007fad54a946c8 in Py_RunMain.cold () from /lib64/libpython3.9.so.1.0
#26 0x00007fad54bd641d in Py_BytesMain () from /lib64/libpython3.9.so.1.0
#27 0x00007fad5462a610 in \__libc_start_call_main () from /lib64/libc.so.6
#28 0x00007fad5462a6c0 in \__libc_start_main_impl () from /lib64/libc.so.6
#29 0x000055fea1942095 in \_start ()