Debugging HowTos

Merb uses ruby-debug (“rdebug”). Odds are good you have it installed already, but if not…

> gem install ruby-debug

To launch merb with ruby-debug enabled add the ”-D” flag:

> merb -D

Hint: If you spend more than a couple minutes using rdebug, you'll want to set up a ~/.rdebugrc file that looks something like this ¹⁾:

set autolist
set autoeval
set autoreload
set forcestep

… and anything else you may find useful

The debugger is activated automatically anytime a debugger statement is encountered in your code. For example:

  def show
    debugger
    # ... the rest of your code ...
  end

Another way to activate the debugger is to launch merb with the ”-C” option, which instructs merb to open the debugger any time you hit Ctrl-C. Note: This feature may be broken

rdebug is a full-featured debugger but, unfortunately, good references are a bit hard to come by. This guide for v0.10.1 , is the best I've found so far.

Feel free to add any merb-specific tips and tricks here.