Kernel not restarting sometimes

import tensorflow is one way to reproduce: clip. Further, 4.1.4 prints INFO-level messages (also shown), which didn’t occur in 4.1.3, now needing manually setting os.environ['TF_CPP_MIN_LOG_LEVEL'] = '1' to disable.

It also doesn’t always reproduce; still unsure how it works exactly.

[impact27]

Fixed by https://github.com/spyder-ide/spyder/pull/19411

If the frontend receives an error while restarting, it will abort. But if the kernel sends an error while closing, then the frontend aborts, even though the new kernel is fine.

[OverLordGoldDragon]

@ccordoba12 Found a different way to reproduce: importing a compiled .c module (.pyd) and calling its method.

C code

#define PY_SSIZE_T_CLEAN
#include <Python.h>

static PyObject *
spam_system(PyObject *self, PyObject *args)
{
    const char *command;
    int sts;

    if (!PyArg_ParseTuple(args, "s", &command))
        return NULL;
    sts = system(command);
    return PyLong_FromLong(sts);
}

static PyMethodDef SpamMethods[] = {
    {"system",  spam_system, METH_VARARGS,
     "Execute a shell command."},
    {NULL, NULL, 0, NULL}        /* Sentinel */
};

static struct PyModuleDef spammodule = {
    PyModuleDef_HEAD_INIT,
    "spam",   /* name of module */
    NULL,     /* module documentation, may be NULL */
    -1,       /* size of per-interpreter state of the module,
                 or -1 if the module keeps state in global variables. */
    SpamMethods
};

PyMODINIT_FUNC
PyInit_spam(void)
{
    return PyModule_Create(&spammodule);
}

setup.py

from distutils.core import setup, Extension

module1 = Extension('spam',
                    sources = ['spammodule.c'])

setup (name = 'PackageName',
       version = '1.0',
       description = 'This is a demo package',
       ext_modules = [module1])

Run python setup.py build, then drag the proper .pyd out of build so that it’s visible to Python, then in separate .py, run

import spam
spam.system('h')

TensorFlow does import from .pyd, so this might explain the problem (though, wasn’t it working for older TFs? They also import .pyd, but above script actually errors, so maybe it reacts to errors - dunno).