Scenario:

• use Tracy\Debugger::enable() and place it after a possible redirect (i.e. to a language-specific url, like http://example.com/ -> http://example.com/en; should not happen in Nette application with standard bootstrap, happened to me in Drupal project using Tracy)
• the redirect occurs when loading Tracy assets (like http://example.com/?_tracy_bar=js&v=2.4.2&XDEBUG_SESSION_STOP=1&XDEBUG_PROFILE=0&XDEBUG_TRACE=0 is redirected to http://example.com/en?_tracy_bar=js&v=2.4.2&XDEBUG_SESSION_STOP=1...
• problem: header_remove('Set-Cookie') is not called from Bar.php when the redirect occurs and the cookie XDEBUG_SESSION=deleted gets into browser

I've proposed a simple solution printing at least console warning to confused developers like me, who would be investigating for hours why XDEBUG stops after first request, will pull request it in a second :)