Bundler 0.9.25, Rails 2.3.8 and vendor/gems has no specification file error

Majority of us have seen this dreadful error after running rake:gems:unpack or a similar command to register gems with the application.

config.gem: Unpacked gem clearance-0.8.8 in vendor/gems has no specification file. Run 'rake gems:refresh_specs' to fix this.

I was under the impression that this happens due to some bug in rails gem dependency management and never expected the same to happen with Bundler. Unfortunately, I was wrong. Just yesterday, I had this error and it’s one of those things that doesn’t really stop your app from working but is very annoying.

There is a fix on Stack Overflow but it might not work if you are using bundler. The command to use remains the same but it needs to be slightly modified. Here are the steps:

This assumes that you get this error with clearance.
Step 1

cd vendor/gems/clearance-0.8.8

Step 2

gem specification ../../cache/clearance-0.8.8.gem > .specification

With bundler the gem files are actually stored in the vendor/cache directory. specification is a gem command that extracts a .specification file from gem file. Here’s full explanation of it.

That’s it. Wasn’t that easy?