You are using an old or stdlib version of json gem

Question

I've seen the following issue mentioned in another thread a few days ago amongst other problems, but the solution for this issue (to me) didn't seem to be addressed.

I recently ran a test on my Ruby 1.9.2-p290 environment and was presented with the following error when I ran a test script:

You are using an old or stdlib version of json gem
Please upgrade to the recent version by adding this to your Gemfile:

gem 'json', '~> 1.7.7'

This issue continued when I created a completely fresh Ruby 1.9.3-p392 environment, running on Windows XP (don't ask). What confuses me is that even when I have json 1.7.7 or 1.8.0 installed (gem list is pasted below), I still get this message when I run my test. It's not really affecting my test results, but the warning is just rather annoying to see each time.

Which Gemfile do I need to add this version into, and where would it be located?

gem list:
bigdecimal (1.1.0)
childprocess (0.3.9)
commonwatir (4.0.0)
ffi (1.8.1 x86-mingw32)
io-console (0.4.2, 0.3)
json (1.8.0, 1.7.7, 1.5.5)
mini_portile (0.5.0)
minitest (5.0.0, 2.5.1)
multi_json (1.7.3)
rake (10.1.0.beta.3, 10.0.4, 0.9.2.2)
rdoc (4.0.1, 3.9.5)
rubygems-update (2.0.3)
rubyzip (0.9.9)
selenium-webdriver (2.32.1)
watir-webdriver (0.6.4)
websocket (1.0.7)
win32-api (1.4.8 x86-mingw32)
win32-process (0.7.2)
windows-api (0.4.2)
windows-pr (1.2.2)

Answer 1

The message is coming from the multi_json gem, and it seems like it could be a bug. I suggest keeping an eye on this GitHub ticket.

If the message is too distressing, you can downgrade multi_json to version 1.6.1 to get rid of it. (At least this works for me.)

UPDATE:

It looks to me like the root of the problem is that while multi_json wants to limit its use of the json and json_pure gems to specific versions, the author of multi_json isn't using the gem method in his code to activate these versions. (It sounds like he thinks Bundler is the only way to specify versions of gems; it isn't.)

Since multi_json will try the oj and yajl-ruby gems before it tries json, using one of those may be the best workaround of all. So you can just install the latest multi_json and then install either oj or yajl-ruby along with it.

Answer 2

Try this:

gem update --system 
gem update