Debug endless WordPress redirect loops while plugins and themes are disabled Blog

OPEN
wp-includes/canonical.php

FIND
// protect against chained redirects
if ( !redirect_canonical($redirect_url, false) ) {

ABOVE, FIND

if ( $do_redirect ) {

AFTER, ADD
# directly after the $do_redirect if line

echo 'Debug in '.__FILE__. ' <br/>Doing redirect <br/>';
echo 'Req: '.$requested_url. '<br/>';
echo 'Red: '.$redirect_url;
die();

Happy debugging 🙂