perllexwarn "tells" me

no warnings 'redefine';
[download]

... but I guess there should be a way to structure your code not to redefine an existing subroutine at all :-).

On Windows (resp. case-insensitive file systems), getting a lot of these for no obvious reason is a sure-fire symptom of loading a module using the wrong case for its name:

use File::Find;
# ... and in a code location far away
use file::find;
[download]

no warnings 'redefine';

Doesn't work for constant subroutines

there should be a way to structure your code not to redefine an existing subroutine at all :-).

In this case, no.

---

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

RIP Neil Armstrong

no warnings "redefine"; # won't help here
require Foo;
delete $INC{"Foo.pm"};
require Foo;
[download]

no warnings "redefine";

Doesn't work for constant subroutines. Yes. It is an unusual requirement to redefine a constant ;)

---

With the rise and rise of 'Social' network sites: 'Computers are making people easier to use everyday'

Examine what is said, not who speaks -- Silence betokens consent -- Love the truth but pardon error.

"Science is about questioning the status quo. Questioning authority".

In the absence of evidence, opinion is indistinguishable from prejudice.

RIP Neil Armstrong

like I said, it doesn't work from outside. for constants the redefinition happens in constant.pm.
you could delete $main::{C}

#!/usr/bin/perl

BEGIN {
    $ENV{'REDEFINE'} = 0;
}
    
use autodie;
use common::sense;
use Env::Export qw/:nowarn REDEFINE/;

sub FOO () { 23 }
sub FOO () { 42 }
[download]

has the same problem with perl < 5.16