downgrade activesupport to work around some bizarre gem interaction.

With this Gemfile:

  source 'http://rubygems.org'
  gem 'json', '= 1.4.6'
  gem 'hashie', '= 0.2.2'
  gem 'activesupport', '= 3.0.2'
  gem 'feedzirra', '= 0.0.24'
  gem 'i18n', '= 0.4.2'

Run this script:

  require 'bundler'
  Bundler.require
  require 'json'
  require 'hashie'
  JSON.pretty_generate(Hashie::Mash.new)

And see this error:

/home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.2/lib/active_support/json/encoding.rb:61:in `options_for': undefined method `merge' for #<JSON::Ext::Generator::State:0xa154e38> (NoMethodError)
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.2/lib/active_support/json/encoding.rb:46:in `block in encode'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.2/lib/active_support/json/encoding.rb:77:in `check_for_circular_references'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.2/lib/active_support/json/encoding.rb:45:in `encode'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.2/lib/active_support/json/encoding.rb:30:in `encode'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/activesupport-3.0.2/lib/active_support/core_ext/object/to_json.rb:20:in `to_json'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/hashie-0.2.2/lib/hashie/hash.rb:19:in `to_json'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/json-1.4.6/lib/json/common.rb:264:in `generate'
  from /home/bronson/.rvm/gems/ruby-1.9.2-p0/gems/json-1.4.6/lib/json/common.rb:264:in `pretty_generate'
  from console:5:in `<main>'

Gemfile

@@ -1,11 +1,19 @@
 source 'http://rubygems.org'
 
+# some weird interaction between a bunch of gems...  Locking activesupport
+# seems to fix it.  If you can run 'JSON.pretty_generate(Hashie::Mash.new)'
+# on the vim-script console then this is not a problem.
+gem 'activesupport' ,'= 3.0.1'
+
+# the pdf magic in mimemagic 0.1.8 is far too loose (recognizes textfiles and zipfiles as pdf)
+# see comments on https://github.com/minad/mimemagic/commit/50078a4d52bb80f525784f6a4cb874fc7d2a03a0#commitcomment-280266
+gem 'mimemagic'   ,'= 0.1.7'
+
 gem 'hpricot'     ,'~> 0.8.2'
 gem 'json'        ,'~> 1.4.6'
 gem 'gitrb'       ,'~> 0.2.7'
 gem 'bzip2-ruby'  ,'~> 0.2.6'
 gem 'mime-types'  ,'~> 1.16'
-gem 'mimemagic'   ,'= 0.1.7'  # can't use 0.1.8, see comments on https://github.com/minad/mimemagic/commit/50078a4d52bb80f525784f6a4cb874fc7d2a03a0#commitcomment-280266
 gem 'octopussy'   ,'~> 0.3.0'
 gem 'hashie'      ,'~> 0.2.2'
 gem 'htmlentities','~> 4.2.1'

Gemfile.lock

@@ -2,7 +2,7 @@ GEM
   remote: http://rubygems.org/
   specs:
     abstract (1.0.0)
-    activesupport (3.0.4)
+    activesupport (3.0.1)
     builder (3.0.0)
     bzip2-ruby (0.2.7)
     crack (0.1.6)
@@ -48,6 +48,7 @@ PLATFORMS
   ruby
 
 DEPENDENCIES
+  activesupport (= 3.0.1)
   bzip2-ruby (~> 0.2.6)
   erubis (~> 2.6.6)
   feedzirra (~> 0.0.24)