Re: test-fcntl-h-c++.cc:32: error: 'open' is not a member of 'gnulib'

[Bruno Haible]

Hi Jim,

> I am ambivalent about pkg-config, and cannot justify
> its use in grep, but will wait until after 2.6 to remove it.

I wasn't asking to remove pkg-config, but only to distribute the complete
source code of aclocal.m4, excluding released versions of Automake. So that
anyone can rebuild aclocal.m4 without gettting trouble if
  - he doesn't have pkg-config on his machine, or
  - he has another version of pkg-config on his machine, or
  - his pkg-config is installed with a different --prefix than autoconf and
    automake.

The freedom to change a configure.ac file, supposedly guaranteed by the GPL,
is practically void if a user gets into lots of trouble during the step of
regenerating aclocal.m4 from configure.ac.

But if you want to drop pkg-config, here's how GNU clisp links with pcre:

  dnl Search for libpcre and define LIBPCRE, LTLIBPCRE and INCPCRE.
  AC_LIB_LINKFLAGS([pcre])

  AC_CHECK_HEADERS(pcre.h pcre/pcre.h, break)
  if test "$ac_cv_header_pcre_h" = "no" -a "$ac_cv_header_pcre_pcre_h" = "no"; 
then
    AC_MSG_ERROR([cannot find PCRE headers])
  fi

  AC_LIB_APPENDTOVAR([LIBS], [$LIBPCRE])
  AC_SEARCH_LIBS(pcre_compile, pcre)
  if test "$ac_cv_search_pcre_compile" = "no"; then
    AC_MSG_ERROR([cannot find PCRE library])
  fi

One can certainly improve on that (restore LIBS afterwards, avoid AC_MSG_ERROR
etc.). Just an idea.

Bruno