Guard + Pry + Mac OS X = :-(
Debugging is critical, especially when you’re learning a new system. At Ibotta, we’re using pry for debugging. Today, I ran into an issue where I had Guard running to automatically run my tests as I made changes. I need a breakpoint, so I set a
binding.pry in a model I wanted to inspect. Upon hitting the breakpoint, I noticed that what I was typing was not being echoed to the screen. I could still execute commands, but I couldn’t see what I was typing. Pretty annoying!
How to Fix It
The reason behind this problem turns out to be the version of Ruby I built using rbenv and ruby-build. It uses the
libedit instead of readline. There are a few ways to fix this problem detailed on Guard’s wiki.
The Easy Way
The easy way for me turned out to be adding rb-readline to my Gemfile, like this:
group :development do gem 'rb-readline' end
The Harder Way
But, of course, I did it the hard way first. I rebuild Ruby with the readline version I had installed on my Mac.
First, install readline:
brew install readline
Then, reinstall the version of Ruby you’re using:
RUBY_CONFIGURE_OPTS=--with-readline-dir=`brew --prefix readline` rbenv install 1.9.3-p286
All of these options are actually defined on the Guard Wiki, so check that out if you’re still having problems.