问题
Out of nowhere, and without changing anything, I've started getting this error (and so did other people on the team).
This is happening for some gems (the ones specifying a git branch) and is only happening when we recreate the environment (in vagrant). We didn't change anything.
Any ideas? More info follows:
Using active_utils (2.0.0) from git://github.com/Shopify/active_utils.git (at v2.0.0)
NoMethodError: undefined method `spec' for nil:NilClass
An error occurred while installing active_utils (2.0.0), and Bundler cannot continue.
Make sure that `gem install active_utils -v '2.0.0'` succeeds before bundling.
Using factory_girl (2.6.5) from https://github.com/thoughtbot/factory_girl (at 2.6.x)
NoMethodError: undefined method `spec' for nil:NilClass
An error occurred while installing factory_girl (2.6.5), and Bundler cannot continue.
Make sure that `gem install factory_girl -v '2.6.5'` succeeds before bundling.
- Running "gem install active_utils -v '2.0.0'" works but bundle always fails.
- Cleared gem cache, but didn't help
Seems like it's all entries in Gemfile specifying a branch that started failing.
gem 'active_utils', :git => 'git://github.com/Shopify/active_utils.git', :branch => 'v2.0.0'
gem "will_paginate", :git => "git://github.com/mislav/will_paginate.git", :branch => "2-3-stable"
回答1:
So, turns out this was caused because of a recent upgrade to RubyGems. Forcing a previous version worked.
gem update --system 2.4.8
回答2:
While there's already an accepted answer, I ran into the same problem.
Ultimately, the cause was I was using an outdated bundler version and updating to the latest version fixed it. More info on the bug from here: https://github.com/bundler/bundler/issues/3560
The bug happens prior to bundler version 1.9.3.
You can update bundler by running gem install bundler
and then deleting the older bundler version via gem uninstall bundler -v old.bundler.version
If you're using rvm, I recommend installing this on the global gemset of your current ruby version by running rvm use @global before doing the install.
来源：https://stackoverflow.com/questions/33733476/nomethoderror-undefined-method-spec-for-nilnilclass-active-utils-factory