Install therubyracer gem on OSX 10.11 El Capitan - bundler

Question

bundle install fails with Make sure that `gem install therubyracer -v '0.12.1'` succeeds before bundling
gem install therubyracer -v '0.12.1' fails with errors which appear to relate to compilation
Prior to this, libv8 gem was having problems but that is now installed thanks to following SO posts.
Guides for fixing rubyracer for Mavericks seem to not work, due to changes in El Capitan?
ln: /usr/bin/cpp: Operation not permitted

Answer 1

Install xcode through app store
Install 'command line tools' for xcode (xcode-select --install)
If using rbenv, after installing ruby you needed rbenv rehash
Assuming you have run gem install bundler and got errors, remove your mess:
gem uninstall libv8
gem uninstall therubyracer
brew rm v8
Install gcc4.2
brew tap homebrew/dupes
brew install apple-gcc42
Install v8
brew tap homebrew/versions
brew install v8-315
brew link --force v8-315
Install gems
gem install libv8 -- --with-system-v8
gem install therubyracer
if you get dyld: lazy symbol binding failed: Symbol not found, #rpbaltazar suggests an alternative:
bundle config --local build.libv8 --with-cxx=/usr/local/bin/g++-4.2
bundle install

Answer 2

I still had issues with #xxjjnn's answer. The following answer from github resolved it. My current setup: El Capitan 10.11.4 and Xcode 7.3.
brew tap homebrew/versions
brew install v8-315
gem install libv8 -v '3.16.14.13' -- --with-system-v8
gem install therubyracer -- --with-v8-dir=/usr/local/opt/v8-315
bundle install

Answer 3

The answer provided on therubyracer Github page worked for me:
brew tap homebrew/versions
brew install v8-315
brew link --force v8-315
gem install libv8 -- --with-system-v8
gem install therubyracer

Answer 4

I updated the gem therubyracer to 0.12.2, then I runned this commands in the rails repository:
$ brew install v8-315
$ bundle config --local build.libv8 --with-system-v8
You are replacing the current local value of build.libv8, which is currently nil
$ bundle config --local build.therubyracer --with-v8-dir=$(brew --prefix v8-315)
You are replacing the current local value of build.therubyracer, which is currently nil
and finally
bundle install

Answer 5

I know this question is specifically about installing therubyracer -v '0.12.1', but the solution really is to upgrade to '0.12.2'.
I've struggled with this on a few projects and always forget that. Then eventually I remember and it all works.
Be sure to clean out anything you've added to bundle config once you don’t need it with bundle config --delete build.libv8.
Here’s the thread on the gem repo about this: https://github.com/cowboyd/therubyracer/issues/398#issuecomment-238161167

Answer 6

(Posting as a comment for readability purposes, but this should be an add-on to the original accepted answer)
After running the accepted answer, I was facing the error described in the comments.
The solution I found helpful for me was running the following
gem uninstall libv8
gem uninstall therubyracer
bundle config --local build.libv8 --with-cxx=/usr/local/bin/g++-4.2
bundle install
Please note that the initial steps of the accepted answer are necessary, namely installing the compiler.

Answer 7

Actually, apple-gcc42 is removed from brew:
apple-gcc42 was deleted from homebrew/core in commit bcba321ea:
Instead, I've installed gcc#4.9
So, following xxjjnn answer, instead of 5 just run:
brew install gcc#4.9

Answer 8

First try to delete your Gemfile.lock and run bundle install again. Gemfile.lock will be created again.
This will work for most cases on El Capitan.
Without that it will just install the same versions mentioned in Gemfile.lock. If you delete this file, bundle install will fetch newest versions of your gems.

Answer 9

If none of the above works for you, follow this guys advice. Uninstalling everything related and upgrading gcc fixed it for me.
Gem install therubyracer -v '0.11.4'?

Answer 10

If you can switch to mini racer, installing it or updating it worked for me similar to this post
How to fix libv8 bad version error
TL;DR bundle update mini_racer