Coding and stuff

A Redcar debugger interface

by Tim Felgentreff ,

Bringing some debugging to Redcar

The Redcar

I have been using the excellent Redcar editor for about a year now, and I must say I am very happy with this project and the pace it’s moving forward at. Hardly a day goes by where there is not some new, hot feature that makes coding easier in this project.

But the best part: this editor is written almost entirely in JRuby, which makes it a breeze to get into the code and start hacking on it.


When working on C extension support for JRuby, I often find myself having to attach a Java debugger and a GDB to the same process. For Java debugging, I used Eclipse, which comes with very handy features like inspection and hot code reloading, but the thing I like most about the Eclipse debug perspective is how it organizes the information about the process.

With GDB’s commandline interface, I often found myself typing bt, info locals, info args at each breakpoint, and returning back to Redcar for context.

Luckily, there are very good frontends for GDB, too, the most sophisticated I could find was the debugger interface for Emacs, which offers me a layout similar to the Eclipse debug perspective. The Emacs debugger interface even came with JDB support. Hurray!

Why Redcar-debug?

I turns out, while I do like Emacs for TeX editing, I prefer programming in Redcar. Switching between Redcar, Eclipse was bad enough, throwing Emacs into that was too much.

This is why I started redcar-debug, the Grand Debugging Interface for Redcar which I have been using for a couple of months now for my JRuby debugging needs.

It currently includes modules for GDB, JDB, RDebug and Hijack support, and it shouldn’t be too hard to add other commandline-driven debuggers to it. And because you can describe a GUI for something best with pictures I have some moving pictures for you, too:

Update The video wasn’t working for some people, so here’s a plain link

This work is licensed under a Creative Commons Attribution-ShareAlike 3.0 Germany License. Any source code included is, unless stated otherwise, licensed under a MIT License. This does not apply for comments (below).