bug#2281: 23.0.90; indeterminate X11 "standard dirs"

Hello!

My Mac has meanwhile three X11 installations:

   1. /usr/X11R6 – Apple's default for Mac OS X 10.1...10.4
   2. /usr/X11   – a self-compiled installation of X11R7.4, Apple  
standard from Mac OS X 10.5 on
   3. /opt       – another X11R7.4 port from MacPorts which produces  
a completely working GNU Emacs 23.x
   4. /sw        – the port of some X11 and other libraries from Fink

So it's not sufficient when configure summarises in the end:

   Where do we find X Windows header files?                Standard dirs
   Where do we find X Windows libraries?                   Standard dirs

Which are the so-called "standard dirs?" A clear path should be  
mentioned here. And probably I'm not the only one experimenting with  
more than one X11 release/installation ...


In GNU Emacs 23.0.90.1 (powerpc-apple-darwin8.11.0, GTK+ Version 2.14.7)
  of 2009-02-11 on localhost
Windowing system distributor `The X.Org Foundation', version  
11.0.10402000
configured using `configure  '--without-sound' '--without-pop' '-- 
with-dbus' '--with-libotf' '--enable-locallisppath=/Library/ 
Application Support/Emacs/calendar23:/Library/Application Support/ 
Emacs' 'PKG_CONFIG_PATH=/opt/local/lib/pkgconfig:/usr/local/lib/ 
pkgconfig:/usr/lib/pkgconfig' 'CFLAGS=-Wno-pointer-sign -H -pipe - 
fPIC -mcpu=7450 -mtune=7450 -fast -mpim-altivec -ftree-vectorize - 
foptimize-register-move -freorder-blocks -freorder-blocks-and- 
partition -fthread-jumps -fpeephole -fno-crossjumping' 'CXXFLAGS=-no- 
cpp-precomp -I/opt/local/include' 'CPPFLAGS=-no-cpp-precomp -I/opt/ 
local/include' 'LDFLAGS=-dead_strip -multiply_defined suppress -L/opt/ 
local/lib' 'PKG_CONFIG=/opt/local/bin/pkg-config''

Important settings:
   value of $LC_ALL: nil
   value of $LC_COLLATE: nil
   value of $LC_CTYPE: de_DE.UTF-8
   value of $LC_MESSAGES: nil
   value of $LC_MONETARY: nil
   value of $LC_NUMERIC: nil
   value of $LC_TIME: nil
   value of $LANG: de_DE.UTF-8
   value of $XMODIFIERS: nil
   locale-coding-system: utf-8-unix
   default-enable-multibyte-characters: t

Major mode: Man

Minor modes in effect:
   show-paren-mode: t
   display-time-mode: t
   tooltip-mode: t
   tool-bar-mode: t
   mouse-wheel-mode: t
   file-name-shadow-mode: t
   global-font-lock-mode: t
   font-lock-mode: t
   blink-cursor-mode: t
   global-auto-composition-mode: t
   auto-composition-mode: t
   auto-encryption-mode: t
   auto-compression-mode: t
   column-number-mode: t
   line-number-mode: t
   transient-mark-mode: t


--
Greetings

   Pete

For some reason, this fortune reminds everyone of Marvin Zelkowitz.