Zend Debugger is a full-featured php debugger engine. Formula was removed
Last version was
php53-zenddebugger requires the following formulae to be installed:
autoconf 2.69 Automatic configure script builder

Recent formula history

Mike McQuaid Deprecate tap.
Mike McQuaid php53-zenddebugger: use <<~EOS.
Andreas Braun Add description for zenddebugger formula
Baptiste Fontaine php53-zenddebugger: audit fix
Andy Blyler php53-zenddebugger: convert from sha1 to sha256

Formula code at GitHub