I stumbled upon an error trying to work with acts_as_solr just after upgrading to Ubuntu 10.04. When trying to start the solr-daemon with

rake solr:start

i suddenly got an error not seen before:

undefined method `closed?' for nil:NilClass
/usr/lib/ruby/1.8/net/http.rb:1060:in `request'
/usr/lib/ruby/1.8/net/http.rb:962:in `request_head'

As the error hints, it’s something to do with the net/http library. After some googling I found out, that it is because Ubuntu 10.04 ships with Ruby 1.8.7, and that this particular version has a bug in the net/http library. Here’s the bug-report and the patch that will help:

http://redmine.ruby-lang.org/issues/show/2708

Hopefully this patch will soon find its way to Canonical’s updates.