use ExtUtils::MakeMaker;
# See lib/ExtUtils/MakeMaker.pm for details of how to influence
# the contents of the Makefile that is written.

WriteMakefile
   (
    'NAME'	=> 'Bar',
    'VERSION_FROM' => 'Bar.pm', # finds $VERSION
defined $ENV{'HACK'} ? (
    'LIBS'	=> ['-L.. -lhack'],   # e.g., '-lm' 
) : (
    'LIBS'	=> [''],   # e.g., '-lm' 
),
    'INC'	=> '',     # e.g., '-I/usr/include/other'
defined $ENV{'CROSSLINK'} ? (
    'OBJECT' => '$(BASEEXT)$(OBJ_EXT) /afs/sipb.mit.edu/user/bert/dev/perl5/dev/ComErr/link_test/Foo/blib/arch/auto/Foo/Foo.so',
) : (),
defined $ENV{'CROSSLINK'} || defined $ENV{'BREAK'} ? (
    'DEFINE'	=> '-DUSE_EXTERN',     # e.g., '-DHAVE_SOMETHING'
) : (),
);