Nginx add argument to every request from parent argument

Question

I have this URL http://www.example.com/?jenkins=FCPI-526-preview-branch and I would like every asset i.e. http://www.example.com/css/app.css to also have the exact same argument as the parent request arguments.

I have tried the following:

1. Setting a header and reading from that header (failed)
2. Setting a cookie and reading from that cookie (failed)
3. Rewrite if the argument is not set and set it. The problem I had with this solution was the argument was not being forwarded from the parent request so it was constantly null therefore rendering an infinite loop.