When including pytime.h:

n file included from /usr/include/python3.5m/Python.h:65:0,
                 from src/package.c:25:
/usr/include/python3.5m/pytime.h:136:56: error: ‘struct timespec’ declared inside parameter list [-Werror]
 PyAPI_FUNC(int) _PyTime_AsTimespec(_PyTime_t t, struct timespec *ts);
                                                        ^
/usr/include/python3.5m/pytime.h:136:56: error: its scope is only this definition or declaration, which is probably not what you want [-Werror]
cc1: all warnings being treated as errors
error: command 'gcc' failed with exit status 1

This is using https://www.python.org/ftp/python/3.5.1/Python-3.5.1.tar.xz

GCC v5.3.0

Using Werror obviously

What platform, C library, etc do you have? According to Posix, struct timespec is normally defined in <time.h>, but can also be gotten via various other include files, many of which are included before "pytime.h".

In particular, <Python.h> includes "pyport.h", which has conditional code for including <time.h>, <sys/select.h> and <sys/stat.h>. All of these should define timespec. It might be useful to check your pyconfig.h file to see if stuff like the following is defined:

/* Define to 1 if you can safely include both <sys/time.h> and <time.h>. */
#define TIME_WITH_SYS_TIME 1

Closing as there isn't enough information here for us to do anything about it and there has been no response from the OP to follow-up questions.