diff -up octave-4.2.0/m4/acinclude.m4.implicit octave-4.2.0/m4/acinclude.m4

--- octave-4.2.0/m4/acinclude.m4.implicit	2016-11-13 08:16:10.000000000 -0700

+++ octave-4.2.0/m4/acinclude.m4	2016-12-06 14:19:48.866621459 -0700

@@ -1646,12 +1646,13 @@ AC_DEFUN([OCTAVE_CHECK_SIZEOF_FORTRAN_IN

       AC_RUN_IFELSE([AC_LANG_PROGRAM([[

           #include <assert.h>

           #include <stdint.h>

-          ]], [[

           #if defined (OCTAVE_ENABLE_64)

             typedef int64_t octave_idx_type;

           #else

             typedef int octave_idx_type;

           #endif

+          void F77_FUNC(foo,FOO) (octave_idx_type*, octave_idx_type**, octave_idx_type**);

+          ]], [[

           octave_idx_type n = 2;

           octave_idx_type in[2];

           octave_idx_type out[2];

diff -up octave-4.2.0/m4/link.m4.implicit octave-4.2.0/m4/link.m4

--- octave-4.2.0/m4/link.m4.implicit	2016-11-13 08:21:54.000000000 -0700

+++ octave-4.2.0/m4/link.m4	2016-12-06 13:52:47.132003993 -0700

@@ -22,6 +22,7 @@ AC_DEFUN([gl_FUNC_LINK],

        AC_RUN_IFELSE(

          [AC_LANG_PROGRAM(

            [[#include <unistd.h>

+             #include <stdio.h>

            ]],

            [[int result = 0;

              if (!link ("conftest.a", "conftest.b/"))