Perl Debugger vs Ruby debug

Perl Debugger is an interactive debugger included with Perl, not a separate program. Running Perl with the `-d` flag loads the debugger and adds source information, allowing users to inspect code, set breakpoints, view stack backtraces, and change variable values. The program must compile correctly before debugging.

Debugger commands support stepping into subroutine calls, stepping over them, and tracing execution. Conditional breakpoints and watches on global expressions can pause a run when specified conditions or changes occur. The `x` command can pretty-print nested data; displaying lexical variables requires PadWalker version 0.08 or higher. Options can be set interactively, through `PERLDB_OPTS`, or in `.perldb` files. Documentation also describes a GUI option through Devel::ptkdb. The debugger does not provide stack-frame information for functions not compiled by Perl, such as C or C++ extension functions, and compile-time executable statements are not stopped, though some can be traced with AutoTrace. Perl is listed for Linux, macOS, and Windows, and the debugger is free.

Ruby debug is a free, BSD-2-Clause open-source debugger for Ruby MRI 2.7 and later, delivered for Linux and self-hosted use. Its console evaluates Ruby expressions, inspects program state, controls execution, sets conditional and exception breakpoints, and enables tracing. The debugger can record execution and replay it by stepping backward through the log. Remote sessions work over UNIX domain sockets or TCP/IP, allowing a console to attach to a running program. An IRB console adds autocompletion, multiline input, and commands including `show_source` and `show_doc`. The `rdbg` command launches Ruby scripts and commands such as Rails, Rake, and RSpec under debugging. Frontends are described for VS Code and Chrome DevTools; VS Code requires the vscode-rdbg extension. Installation uses `gem install debug` or a Gemfile entry. The project reports no performance penalty when not stepping and with no breakpoints set. It warns that remote messages are unencrypted and that `debug/open_nonstop` can expose access without stopping the program.