[BUG] calling multiple pybind11 scoped env which calls cppyy

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What version (or hash if on master) of pybind11 are you using?

2.13.6

Problem description

i have embedded python with my QT (c++) solution. i call a c++ function which uses pybind11 to get me into python, which in turn sets up a cppyy encapsualtion of a simpe c++ function. it works fine, but call it again it crashes. below is the crash report

"
Hello, World!
['/home/simon/Desktop/Code/VirtEnv/lib/python3.12/site-packages/', '/home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/', '', '/usr/lib/python312.zip', '/usr/lib/python3.12', '/usr/lib/python3.12/lib-dynload', '/usr/local/lib/python3.12/dist-packages', '/usr/lib/python3/dist-packages', '/usr/lib/python3.12/dist-packages']
here
there
done
free(): invalid size
*** Break *** abort
#0 0x00007f9cb8710893 in __GI___wait4 (pid=4609, stat_loc=stat_loc
entry=0x7fff23a04f68, options=options
entry=0, usage=usage
entry=0x0) at ../sysdeps/unix/sysv/linux/wait4.c:30
#1 0x00007f9cb87109e7 in __GI___waitpid (pid=, stat_loc=stat_loc
entry=0x7fff23a04f68, options=options
entry=0) at ./posix/waitpid.c:38
#2 0x00007f9cb866891b in do_system (line=) at ../sysdeps/posix/system.c:172
#3 0x00007f9cb5ba1c15 in CppyyLegacy::TUnixSystem::StackTrace() () from /home/simon/Desktop/Code/VirtEnv/lib/python3.12/site-packages/cppyy_backend/lib/libCoreLegacy.so
#4 0x00007f9cb5cd94bf in (anonymous namespace)::do_trace (sig=5) at src/clingwrapper.cxx:249
#5 (anonymous namespace)::TExceptionHandlerImp::HandleException (this=, sig=5) at src/clingwrapper.cxx:262
.....
#42 0x00007f9cb8ef0ae6 in ?? () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#43 0x00007f9cb8ef0bf9 in ?? () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#44 0x00007f9cb8ef41bf in PyRun_StringFlags () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#45 0x000055ea7e523055 in pybind11::eval<(pybind11::eval_mode)2> (expr=..., global=..., local=...) at /usr/include/pybind11/eval.h:74
#46 0x000055ea7e4fcb2b in pybind11::exec (expr=..., global=..., local=...) at /usr/include/pybind11/eval.h:89
#47 0x000055ea7e4fb462 in Test002 () at /home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/main.cpp:147
#48 0x000055ea7e4fb1bb in main (argc=1, argv=0x7fff23a09058) at /home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/main.cpp:32
*** Break *** abort
#0 0x00007f9cb8710893 in __GI___wait4 (pid=4848, stat_loc=stat_loc
entry=0x7fff23a04f68, options=options
entry=0, usage=usage
entry=0x0) at ../sysdeps/unix/sysv/linux/wait4.c:30
#1 0x00007f9cb87109e7 in __GI___waitpid (pid=, stat_loc=stat_loc
entry=0x7fff23a04f68, options=options
entry=0) at ./posix/waitpid.c:38
#2 0x00007f9cb866891b in do_system (line=) at ../sysdeps/posix/system.c:172
#3 0x00007f9cb5ba1c15 in CppyyLegacy::TUnixSystem::StackTrace() () from /home/simon/Desktop/Code/VirtEnv/lib/python3.12/site-packages/cppyy_backend/lib/libCoreLegacy.so
#4 0x00007f9cb5cd93cf in (anonymous namespace)::do_trace (sig=5) at src/clingwrapper.cxx:249
#5 (anonymous namespace)::TExceptionHandlerImp::HandleException (this=, sig=5) at src/clingwrapper.cxx:268
....
#41 0x00007f9cb8e97507 in PyEval_EvalCode () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#42 0x00007f9cb8ef0ae6 in ?? () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#43 0x00007f9cb8ef0bf9 in ?? () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#44 0x00007f9cb8ef41bf in PyRun_StringFlags () from /lib/x86_64-linux-gnu/libpython3.12.so.1.0
#45 0x000055ea7e523055 in pybind11::eval<(pybind11::eval_mode)2> (expr=..., global=..., local=...) at /usr/include/pybind11/eval.h:74
#46 0x000055ea7e4fcb2b in pybind11::exec (expr=..., global=..., local=...) at /usr/include/pybind11/eval.h:89
#47 0x000055ea7e4fb462 in Test002 () at /home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/main.cpp:147
#48 0x000055ea7e4fb1bb in main (argc=1, argv=0x7fff23a09058) at /home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/main.cpp:32
13:33:11: /home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/build/Desktop_Qt_6_7_2-Debug/Test_pybind11_cppyy_001 exited with code 133
"

when run from with a debugger:
"
Hello, World!
['/home/simon/Desktop/Code/VirtEnv/lib/python3.12/site-packages/', '/home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/', '', '/usr/lib/python312.zip', '/usr/lib/python3.12', '/usr/lib/python3.12/lib-dynload', '/usr/local/lib/python3.12/dist-packages', '/usr/lib/python3/dist-packages', '/usr/lib/python3.12/dist-packages']
here
there
done
free(): invalid size
44 ./nptl/pthread_kill.c: No such file or directory
81 ../sysdeps/unix/sysv/linux/internal-signals.h: No such file or directory
50 ./nptl/pthread_kill.c: No such file or directory
89 ../sysdeps/unix/sysv/linux/internal-signals.h: No such file or directory
69 ./nptl/pthread_kill.c: No such file or directory
"

Reproducible example code

as called from my QT solution:
"
//
void Test002()
{
//
py::scoped_interpreter guard{};
//
QString qPythonDir("/home/simon/Code/QT/Test_pybind11/Test_pybind11_cppyy_001/");
QString qPythonCommand("");
//
auto locals = py::dict();
auto globals = py::dict();
//
qPythonCommand += "import sys\n";
qPythonCommand += "sys.path.insert(0, '";
qPythonCommand += qPythonDir.toStdString().c_str();
qPythonCommand += "')\n";
qPythonCommand += "sys.path.insert(0, '/home/simon/Desktop/Code/VirtEnv/lib/python3.12/site-packages/')\n";
qPythonCommand += "print(sys.path)\n";
py::exec(qPythonCommand.toStdString().c_str(), py::globals(), locals);
//
qPythonCommand =
R"PY(
import cppyy

cppyy.cppdef("""
#include
void hello()
{
std::cout << "Hello, World!" << std::endl;
}
""")

def runCPP():
global cppyy
print("here")
try:
cppyy.gbl.hello()
print("there")
except Exception as e:
print("Exception: ", e)
print("done")
)PY";

//
py::exec(qPythonCommand.toStdString().c_str(), py::globals(), locals);
//
py::object func = locals["runCPP"];
func();
//
}
"

similar idea to above, but this time no pybind11 and directly from with python. works multiple times.
"
import cppyy

cppyy.cppdef(r"""
#include
void hello() {
std::cout << "Hello, World!" << std::endl;
}
""")

def runCPP():
print("here")
try:
cppyy.gbl.hello()
print("there")
except Exception as e:
print("Exception: ", e)
print("done")
"

Is this a regression? Put the last known working version here if it is.

Not a regression

Reproduce the second invocation of Test002 in main.cpp, especially around lines 32 and 147, using the embedded Python and cppyy setup shown. Read pybind11::exec and pybind11::eval in eval.h alongside the crash trace. Done means the same operation can be called multiple times without the reported invalid-size abort, with a regression check for repeated calls.