Force bundler to rebuild your Ruby on Rails project gemset

I got myself into a bad place after migrating a Rails project to a newer version of Ruby where my gemset was built with the wrong native libraries (rbenv rehash?).

Resulting error when running rspec:

dyld: lazy symbol binding failed: Symbol not found: _rb_funcall2

I had to delete and rebuild my gems but bundler itself doesn’t offer a pristine option.

The easiest way I found was to temporarily remove all gems from my Gemfile so that my Gemfile looked like.

source 'https://rubygems.org'

ruby '2.1.2'

Then:

bundle clean –force

Then undo and re-save my complete Gemfile and:

bundle install

Good to go.