Ruby Bundler attempts to resinstall already installed Gem

I had to uninstall and rebuild json gem on my Windows machine, because the gem that was installed o开发者_开发问答riginally caused NoMethodError (described here). I issued the following commands:

gem uninstall json --all
gem install json --platform=ruby

This built json 1.4.6 and everything worked fine. However, later I issued a bundler command:

bundle update

I saw that Bundler reported "installing json (1.4.6)". After that the error came back, so I had to re-install json again.

I wonder what causes Bundler to reinstall the gem that is already present on the system with matching version number.

The reason is that bundler attempts to install the binary version of json for your platform, while you manually installed the ruby platform one (I believe to workaround other issues of JSON gem)

I will recommend you uninstall json gem that gets installed by bundler after your update.

bundle update
gem uninstall json --platform=x86-mingw32

Also raise this bug to Bundler developers in their issue tracker and their mailing list

Sorry for not been more helpful, but there is no known answer to your issue.