I have had some issues.

README.md

@@ -1,10 +1,10 @@
 PartialMap
 ==========
 
-Too many partials in your project? Can't figure out if the hip bone 
+Too many partials in your project? Can't figure out if the hip bone
 connects to the thighbone or the cheekbone? Let PartialMap help :)
 
-    script/plugin install git@github.com:skwp/PartialMap.git
+    script/rails plugin install git@github.com:skwp/PartialMap.git
 
 Usage
 =======

lib/formatters/base_formatter.rb

@@ -10,7 +10,7 @@ def list(list); raise NotImplementedError; end
     def link_to_partial(file); raise NotImplementedError; end
 
     def clean_path(path)
-      base_path = File.join(RAILS_ROOT,'app/views/')
+      base_path = File.join(::Rails.root.to_s,'app/views/')
       cleaned_path="#{path.gsub(base_path,"")}"
     end
 

lib/partial_map.rb

@@ -1,4 +1,4 @@
-require 'pathname' 
+require 'pathname'
 Dir["#{File.dirname(__FILE__)}/formatters/**"].each {|f| require f; puts f}
 
 # Parse a directory looking for top level files, then recurse
@@ -7,19 +7,19 @@
 # every level, that are only closed once the recursion ends.
 # Oh well.
 #
-# TODO: 
+# TODO:
 #  * make it more efficient by logging entries in a table and then revisiting them.
 #  * handle calls from the view to helpers that render partials (advanced)
 #
 class String; def titleize; self[0,1].upcase + self[1,self.size].downcase; end; end; #:nodoc:
-  
-module PartialMap 
+
+module PartialMap
 
   class RailsViewTree
     attr_reader :all_partials
 
     def initialize(root_path, callback)
-      @all_partials = Dir[File.join(RAILS_ROOT,'app','views','**','**')].select {|file| is_partial?(file)}
+      @all_partials = Dir[File.join(::Rails.root.to_s,'app','views','**','**')].select {|file| is_partial?(file)}
       @callback = callback
       find_views(root_path)
     end
@@ -44,27 +44,27 @@ class Parser
     def initialize(formatter)
       @formatter = formatter
     end
-    
+
     def draw_partial_map(starting_path)
       puts @formatter.head
       @tree = RailsViewTree.new(starting_path, self)
       puts @formatter.foot
     end
 
-    def list_subpartials(file, level=0) 
+    def list_subpartials(file, level=0)
       # Find the partial matching the name we're looking for
       # since it may end in .rhtml, .html.erb, etc
-      output_heading = @formatter.partial(file, level)      
+      output_heading = @formatter.partial(file, level)
       output=""
 
       subpartials_found=0
-      
+
       tracked_partials={}
 
       File.open(file).each do |line|
         if line =~ /render\s+:partial\s+=>\s+['"]([\w\d\/]+)/
           # if partial has a slash, we want to underscore the last part of it
-          # 
+          #
           partial_reference = $1
           # debug "Parsed partial path #{partial_reference}"
 
@@ -74,17 +74,17 @@ def list_subpartials(file, level=0)
             components = partial_reference.split('/')
             partial_name, partial_path = components.pop, components.join('/')
             # debug "Path includes a slash so we're going to look at the relative path #{partial_path} name #{partial_name}"
-            partial_path = File.join(RAILS_ROOT, "app/views", partial_path, "_#{partial_name}")
+            partial_path = File.join(::Rails.root.to_s, "app/views", partial_path, "_#{partial_name}")
           else
             partial_path = File.join(File.dirname(file), "_#{partial_reference}")
           end
 
           # debug "Searching #{partial_path}"
           partial_filename = Dir[partial_path + "*"].first # find the actual fileame
 
-          unless tracked_partials[partial_filename]
+          unless partial_filename.nil? || tracked_partials[partial_filename]
             subpartials_found += 1
-            output << list_subpartials(partial_filename,level+1)  
+            output << list_subpartials(partial_filename,level+1)
             tracked_partials[partial_filename] = true
           end
         end
@@ -96,7 +96,7 @@ def list_subpartials(file, level=0)
       end
 
       return output_heading
-    end  
-  
+    end
+
   end # class
 end # module

lib/tasks/partial_map.rake

@@ -3,11 +3,11 @@ namespace(:partialmap) do
 
   desc "Show a tree of all the view partials."
   task(:text) do
-    PartialMap::Parser.new(PartialMap::PlainFormatter.new).draw_partial_map(File.join(RAILS_ROOT,'app/views'))
+    PartialMap::Parser.new(PartialMap::PlainFormatter.new).draw_partial_map(File.join(::Rails.root.to_s,'app/views'))
   end
 
   desc "Show a tree of all the view partials."
   task(:html) do
-    PartialMap::Parser.new(PartialMap::HtmlFormatter.new).draw_partial_map(File.join(RAILS_ROOT,'app/views'))
+    PartialMap::Parser.new(PartialMap::HtmlFormatter.new).draw_partial_map(File.join(::Rails.root.to_s,'app/views'))
   end
 end