I'm on OS X 10.8 with XCode 4.4, Ruby 1.9.3, and Rails 3.2.
When I clone my rails project from git and run:
bundle install
I get:
Installing json (1.7.4)
Errno::EPERM: Operation not permitted - /Users/myuser/.rvm/gems/ruby-1.9.3-p0/gems/json-1.7.4/.gitignore
An error occurred while installing json (1.7.4), and Bundler cannot continue.
Make sure that gem install json -v '1.7.4' succeeds before bundling.
Then I try:
gem install json -v '1.7.4'
and get:
ERROR: While executing gem ... (Errno::EPERM) Operation not permitted - /Users/scalessec/.rvm/gems/ruby-1.9.3-p0/gems/json-1.7.4/.gitignore
Okay. Permissions issue, right? Let's try:
sudo gem install json -v '1.7.4'
No go. Here's what I get:
Building native extensions. This could take a while... ERROR: Error installing json: ERROR: Failed to build gem native extension.
/Users/myuser/.rvm/rubies/ruby-1.9.3-p0/bin/ruby extconf.rb creating Makefile
make compiling generator.c make: /usr/bin/gcc-4.2: Permission denied make: * [generator.o] Error 1
What the heck?
I am not sure, but I upgraded to OS X 10.8 2 days ago (from Lion, where my Rails configuration worked fine). And I had the same JSON 1.7.4 issue.
Eventually, I solved the problem by noticing that Xcode's command line tools were NOT installed (but they were on OS X 10.7!). I just reinstalled CLI tools in Xcode and that JSON 1.7.4 issue disappeared.
Also just in case it's helpful, check out this guide: https://thoughtbot.com/blog/the-hitchhikers-guide-to-riding-a-mountain-lion