While examining AIX test-suite errors determined that this is not unique to AIX.

michael@x050:~/gnome/glib-2.43.3$ lsb_release -a
No LSB modules are available.
Distributor ID: Ubuntu
Description:    Ubuntu 12.04.5 LTS
Release:        12.04
Codename:       precise

root@x050:/home/michael/gnome/glib-2.43.3# glib/tests/fileutils                                                                                                 
/fileutils/build-path: OK
/fileutils/build-pathv: OK
/fileutils/build-filename: OK
/fileutils/build-filenamev: OK
/fileutils/mkdir-with-parents: OK
/fileutils/format-size-for-display: OK
/fileutils/errors: OK
/fileutils/basename: OK
/fileutils/dir-make-tmp: OK
/fileutils/file-open-tmp: OK
/fileutils/mkstemp: OK
/fileutils/mkdtemp: OK
/fileutils/set-contents: OK
/fileutils/read-link: OK
/fileutils/stdio-wrappers: **
GLib:ERROR:fileutils.c:864:test_stdio_wrappers: assertion failed: (errno == EACCES)
Aborted (core dumped)
root@x050:/home/michael/gnome/glib-2.43.3# find . -name mkdir-test -ls                                                                                              
684103    4 drw-r--r--   2 root     root         4096 Feb  2 10:26 ./mkdir-test
root@x050:/home/michael/gnome/glib-2.43.3# ls -l mkdir-test
total 0
root@x050:/home/michael/gnome/glib-2.43.3# rmdir mkdir-test
root@x050:/home/michael/gnome/glib-2.43.3# 

root@x050:/home/michael/gnome/glib-2.43.3# logout
michael@x050:~/gnome/glib-2.43.3$ find . -name mkdir-test
michael@x050:~/gnome/glib-2.43.3$ glib/tests/fileutils
/fileutils/build-path: OK
/fileutils/build-pathv: OK
/fileutils/build-filename: OK
/fileutils/build-filenamev: OK
/fileutils/mkdir-with-parents: OK
/fileutils/format-size-for-display: OK
/fileutils/errors: OK
/fileutils/basename: OK
/fileutils/dir-make-tmp: OK
/fileutils/file-open-tmp: OK
/fileutils/mkstemp: OK
/fileutils/mkdtemp: OK
/fileutils/set-contents: OK
/fileutils/read-link: OK
/fileutils/stdio-wrappers: OK
michael@x050:~/gnome/glib-2.43.3$ find . -name mkdir-test
michael@x050:~/gnome/glib-2.43.3$ 

Snippet from glib/tests/fileutils.c

  +840  static void
  +841  test_stdio_wrappers (void)
  +842  {
  +843    GStatBuf buf;
  +844    gchar *cwd, *path;
  +845    gint ret;
  +846    struct utimbuf ut;
  +847    GError *error = NULL;
  +848
  +849    g_remove ("mkdir-test/test-create");
  +850    g_rmdir ("mkdir-test");
  +851
  +852    ret = g_stat ("mkdir-test", &buf);
  +853    g_assert (ret == -1);
  +854    ret = g_mkdir ("mkdir-test", 0666);
  +855    g_assert (ret == 0);
  +856    ret = g_stat ("mkdir-test", &buf);
  +857    g_assert (ret == 0);
  +858    g_assert (S_ISDIR (buf.st_mode));
  +859
  +860    cwd = g_get_current_dir ();
  +861    path = g_build_filename (cwd, "mkdir-test", NULL);
  +862    g_free (cwd);
  +863    ret = g_chdir (path);
  +864    g_assert (errno == EACCES);
  +865    g_assert (ret == -1);
  +866    ret = g_chmod (path, 0777);

NOTE: on failure the directory mkdir-test may be remaining (on AIX including the core file, which causes a false error - according to test-logic - because rmdir fails when a directory is not empty). IMHO, either at beginning of test, or at end, should verify that mkdir-test is removed (probably at beginning).