[sisyphus] ld -L/usr/X11R6/lib как передать это в ./configure

[AVL]

есть стандартный метод добавить путь в поиск библиотек.
уже который раз собираю прогу и натыкаюсь на один и тотже сценарий.
./configure
.....
checking for glBegin in -lGL... no
configure: error: OpenGL is needed

знаю что надо добавить -L/usr/X11R6/lib
а как это сделать корректно?
какая это опция?

[avl на perec CriticalMass-0.93]$ ./configure --help
Usage: configure [options] [host]
Options: [defaults in brackets after descriptions]
Configuration:
  --cache-file=FILE       cache test results in FILE
  --help                  print this message
  --no-create             do not create output files
  --quiet, --silent       do not print `checking...' messages
  --version               print the version of autoconf that created configure
Directory and file names:
  --prefix=PREFIX         install architecture-independent files in PREFIX
                          [/usr/local]
  --exec-prefix=EPREFIX   install architecture-dependent files in EPREFIX
                          [same as prefix]
  --bindir=DIR            user executables in DIR [EPREFIX/bin]
  --sbindir=DIR           system admin executables in DIR [EPREFIX/sbin]
  --libexecdir=DIR        program executables in DIR [EPREFIX/libexec]
  --datadir=DIR           read-only architecture-independent data in DIR
                          [PREFIX/share]
  --sysconfdir=DIR        read-only single-machine data in DIR [PREFIX/etc]
  --sharedstatedir=DIR    modifiable architecture-independent data in DIR
                          [PREFIX/com]
  --localstatedir=DIR     modifiable single-machine data in DIR [PREFIX/var]
  --libdir=DIR            object code libraries in DIR [EPREFIX/lib]
  --includedir=DIR        C header files in DIR [PREFIX/include]
  --oldincludedir=DIR     C header files for non-gcc in DIR [/usr/include]
  --infodir=DIR           info documentation in DIR [PREFIX/info]
  --mandir=DIR            man documentation in DIR [PREFIX/man]
  --srcdir=DIR            find the sources in DIR [configure dir or ..]
  --program-prefix=PREFIX prepend PREFIX to installed program names
  --program-suffix=SUFFIX append SUFFIX to installed program names
  --program-transform-name=PROGRAM
                          run sed PROGRAM on installed program names
Host type:
  --build=BUILD           configure for building on BUILD [BUILD=HOST]
  --host=HOST             configure for HOST [guessed]
  --target=TARGET         configure for TARGET [TARGET=HOST]
Features and packages:
  --disable-FEATURE       do not include FEATURE (same as --enable-FEATURE=no)
  --enable-FEATURE[=ARG]  include FEATURE [ARG=yes]
  --with-PACKAGE[=ARG]    use PACKAGE [ARG=yes]
  --without-PACKAGE       do not use PACKAGE (same as --with-PACKAGE=no)
  --x-includes=DIR        X include files are in DIR
  --x-libraries=DIR       X library files are in DIR
--enable and --with options recognized:
  --enable-debug               Enable debugging [default=off]
  --enable-trace               Enable tracing [default=off]
  --enable-optimize=[level]    Enable optimization [default=2]



и каким образом работает этот код в configure

    echo $ac_n "checking for glBegin in -lGL""... $ac_c" 1>&6
echo "configure:1633: checking for glBegin in -lGL" >&5
ac_lib_var=`echo GL'_'glBegin | sed 'y%./+-%__p_%'`
LIBS="-lGL  $LIBS"
    ac_tr_lib=HAVE_LIB`echo GL | sed -e 's/[^a-zA-Z0-9_]/_/g' \
  LIBS="-lGL $LIBS"
{ echo "configure: error: OpenGL is needed" 1>&2; exit 1; }

как он отыскивает библиотеку?