libregexp-debugger-perl 0.002004-1 (amd64 binary) in ubuntu focal

 Regexp::Debugger is a module that helps tame unruly regexes by
 providing live interactive run-time visualizations of any regex in a
 Perl code. The debugger allows one to track capture variables, follow
 recursive subpattern matches, set break-points within a regex match,
 and even step backwards through the matching process to work out
 exactly where things started going so horribly wrong.
 .
 When you load this module, any regex in the same lexical scope will be
 visually (and interactively) debugged as it matches.
 .
 In addition to the Perl module, the package also contains the
 module's commandline frontend rxrx.