What does “WARN Could not determine content-length of response body.” mean and how to I get rid of it?

Question

Since upgrading to Rails 3.1 I\'m seeing this warning message in my development log:

WARN Could not determine content-length of response body. Set co

Answer 1

If you're using .rvm, do this to fix it...

As mentioned by João Soares, all credits to him, this is what you can do if you wan't to get rid of this warning on development.

1. Use your favorite editor to open this file:

   ~/.rvm/rubies//lib/ruby/1.9.1/webrick/httpresponse.rb
   

2. Go to the line that contains this(for me it was really line 206):

   if chunked? || @header['content-length']
   

3. Change it, taken from this patch, to this:

   if chunked? || @header['content-length'] || @status == 304 || @status == 204
   

4. Save the file and eventually restart your rails server