Error when trying to build Python 3.6.3 on Irix 6.5

gistfile1.txt

nekoware/include -I/usr/include -I/usr/nekoware/include -I/usr/include  -DPy_BUILD_CORE -o Python/pythonrun.o Python/pythonrun.c
c99 WARNING:  -O conflicts with -O3; using latter value (-O3)
cc-1171 c99: WARNING File = Python/pythonrun.c, Line = 1366
  The indicated expression has no effect.

              offset = (int)PyUnicode_GET_LENGTH(errtext);
                            ^

        c99 -c  -DNDEBUG -O -O3 -mips4 -I/usr/nekoware/include -TARG:platform=IP27:proc=r10000 -O3 -mips4 -I/usr/nekoware/include -TARG:platform=IP27:proc=r10000     -I. -I./Include -I/usr/nekoware/include -I/usr/include -I/usr/nekoware/include -I/usr/include  -DPy_BUILD_CORE -o Python/pytime.o Python/pytime.c
c99 WARNING:  -O conflicts with -O3; using latter value (-O3)
cc-1020 c99: ERROR File = Python/pytime.c, Line = 716
  The identifier "CLOCK_MONOTONIC" is undefined.

      const clockid_t clk_id = CLOCK_MONOTONIC;
                               ^

1 error detected in the compilation of "Python/pytime.c".
*** Error code 2 (bu21)