Hmm...that still doesn't work for me. I'm on a Win32 system though, so I tried: 
set PERL5LIB=perl5lib;%PERL5LIB%
perl -Mifdef=DEBUGGING foo.pl

[download]
I also tried changing foo.pl like so: 
# ./foo.pl:
use lib './perl5lib';
use ifdef qw/DEBUGGING/;
use Bar;

=begin DEBUGGING
die "limbo";
=cut

die "outer death";
__END__

[download]

Here, the 'use lib' clearly comes before 'use ifdef', but still no luck.

I should also note that, unexpectedly, this doesn't output 'limbo' either (when run as 'perl foo.pl'). However, that is another issue that is, I believe, unrelated to 'use lib'. In the thread I originally referenced, it indicates that "this pragma is only intended to be called from the commandline" anyway.

In reply to Re^4: ifdef in modules by clee
in thread ifdef in modules by Anonymous Monk

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