Question

Whenever I enter a gem command, such as

gem "tilt"

or

gem "mysql"

I get this error:

While executing gem ... <RuntimeError>
Unknown command tilt

When I run gem list, both tilt and mysql show up on the list, so they are installed. In fact, I get this error with every item on the list. What could be causing this?

Answer 1

gem isn’t lying to you, they aren’t valid gem commands.

Perhaps you’re confusing the command line with Bundler? For example, adding

gem "tilt"

to a Gemfile and running bundle install will install tilt. But Bundler uses its own syntax, and isn’t a shell script. To install tilt using the gem binary directly you’d have to do:

gem install tilt

Running gem help will give you a list of gem‘s command line arguments.