Problem scenario: You are running gem install *.gem and it hangs. This stalling appears to be a freeze. You wait several minutes and nothing happens. You are waiting for a message or a new prompt.
Solution: Control-C to get out of it. Try it again with the "-V" flag like this:
gem install contInt.gem -V
# This time be patient. Sometimes these commands can take more than 10 minutes to return a message. The -V flag will provide messages (or more detailed messages) as to the problem you are experiencing. The -V flag and be placed immediately after the "gem install " or at the very end. The -V flag is interchangeable with the "--verbose" flag.