After the AC_TYPE_GETGROUPS patch I just sent and one more I have stacked up locally, the very last use of AC_EGREP_CPP and/or AC_EGREP_HEADER in a stock Autoconf macro will be in AC_PROG_GCC_TRADITIONAL, which does this: AC_DEFUN([AC_PROG_GCC_TRADITIONAL], [AC_REQUIRE([AC_PROG_CC])dnl if test $ac_cv_c_compiler_gnu = yes; then AC_CACHE_CHECK(whether $CC needs -traditional, ac_cv_prog_gcc_traditional, [ ac_pattern="Autoconf.*'x'" AC_EGREP_CPP($ac_pattern, [#include <sgtty.h> Autoconf TIOCGETP], ac_cv_prog_gcc_traditional=yes, ac_cv_prog_gcc_traditional=no) if test $ac_cv_prog_gcc_traditional = no; then AC_EGREP_CPP($ac_pattern, [#include <termio.h> Autoconf TCGETA], ac_cv_prog_gcc_traditional=yes) fi]) if test $ac_cv_prog_gcc_traditional = yes; then CC="$CC -traditional" fi fi ])# AC_PROG_GCC_TRADITIONAL This is logic from solidly before my time -- I only have personal experience with the generation of Unixes including SunOS 4.1 and later. However, it looks to me as though this is testing for a problem with very old <sgtty.h> and/or <termio.h>, which wouldn't define some of the macros they were supposed to define if preprocessed by an ISO C - compliant compiler. Does anyone remember enough to know if that guess is accurate? Do you remember which systems were affected? I presume they would've had their own C compiler and this was in aid of using GCC as a third- party compiler. Given that we are officially dropping support for "traditional" C compilers as of the planned 2.73, and also given that GCC hasn't supported compilation in -traditional mode since, um, 2001 give or take a year, IIRC... Should we just delete this entire thing, or does it still serve a purpose somehow? zw