OK! NDK version is 19.1.5304403

Cool, so I uploaded the output of configure (attachments)

Sorry for the confusion about pyconfig.h, what I was trying to say is after providing ac_cv_pthread_is_default=yes to configure I get errors in make:

Python/pytime.c:911:9: error: implicit declaration of function 'pytime_fromtimespec' is invalid in C99 [-Werror,-Wimplicit-function-declaration]
    if (pytime_fromtimespec(tp, &ts, raise) < 0) {
        ^
Python/pytime.c:911:9: note: did you mean 'pytime_fromtimeval'?
Python/pytime.c:336:1: note: 'pytime_fromtimeval' declared here
pytime_fromtimeval(_PyTime_t *tp, struct timeval *tv, int raise)
^
Python/pytime.c:911:9: warning: this function declaration is not a prototype [-Wstrict-prototypes]
    if (pytime_fromtimespec(tp, &ts, raise) < 0) {
        ^