Move conflict message into conflict class

Library/Homebrew/formula.rb

@@ -721,19 +721,7 @@ private
     end
 
     def conflicts_with formula, opts={}
-      message = <<-EOS.undent
+      dependencies.add ConflictRequirement.new(formula, name, opts)
-      #{formula} cannot be installed alongside #{name.downcase}.
-      EOS
-      message << "This is because #{opts[:because]}\n" if opts[:because]
-      unless ARGV.force? then message << <<-EOS.undent
-        Please `brew unlink #{formula}` before continuing. Unlinking removes
-        the formula's symlinks from #{HOMEBREW_PREFIX}. You can link the
-        formula again after the install finishes. You can --force this install
-        but the build may fail or cause obscure side-effects in the end-binary.
-        EOS
-      end
-
-      dependencies.add ConflictRequirement.new(formula, message)
     end
 
     def skip_clean *paths

Library/Homebrew/requirements.rb

@@ -177,12 +177,23 @@ end
 class ConflictRequirement < Requirement
   attr_reader :formula
 
-  def initialize formula, message
+  def initialize formula, name, opts={}
     @formula = formula
-    @message = message
+    @name = name
+    @opts = opts
   end
 
-  def message; @message; end
+  def message
+    message = "#{@name.downcase} cannot be installed alongside #{@formula}.\n"
+    message << "This is because #{@opts[:because]}\n" if @opts[:because]
+    message << <<-EOS.undent unless ARGV.force?
+      Please `brew unlink #{@formula}` before continuing. Unlinking removes
+      the formula's symlinks from #{HOMEBREW_PREFIX}. You can link the
+      formula again after the install finishes. You can --force this install
+      but the build may fail or cause obscure side-effects in the end-binary.
+    EOS
+    message
+  end
 
   def satisfied?
     keg = Formula.factory(@formula).prefix