+
+dnl Not needed yet, because dup3 is unconditionally replaced.
+dnl dnl Replace dup3() for supporting the gnulib-defined fchdir() function,
+dnl dnl to keep fchdir's bookkeeping up-to-date.
+dnl m4_ifdef([gl_FUNC_FCHDIR], [
+dnl gl_TEST_FCHDIR
+dnl if test $HAVE_FCHDIR = 0; then
+dnl REPLACE_DUP3=1
+dnl fi
+dnl ])