Using rbenv with emacs

March 10, 2012

tl;dr - If you’re using rbenv make sure to add the bin and shims to your editors $PATH.

Previously I wrote about switching to rbenv. The gist of the post is that RVM is a great tool for developers but relies heavily on your shell. Thus, rbenv may be a better fit for your server environment.

I’m actually using rbenv on my home desktop now and that means it needs to work with emacs. The most obvious break is flymake-mode which essentially runs ruby -c on your behalf. The problem should be obvious: the ruby I need emacs to run is not on the $PATH. So lets add it:

;; Setting rbenv path
(setenv "PATH" (concat (getenv "HOME") "/.rbenv/shims:" (getenv "HOME") "/.rbenv/bin:" (getenv "PATH")))
(setq exec-path (cons (concat (getenv "HOME") "/.rbenv/shims") (cons (concat (getenv "HOME") "/.rbenv/bin") exec-path)))

You can then use M-x eval-region to execute the code. Revert any open buffers with C-c r to rerun hooks. Your trouble should go away!

Note that this fixes a lot of problems, including any gem binaries that other modes require (e.g. compiling SASS comes to mind).

Happy emacsing!