Modify MultipleVersionsInstalledError to have a generic message

Library/Homebrew/cli/args.rb

@@ -246,16 +246,21 @@ module Homebrew
         require "formula"
         require "missing_formula"
 
+        puts 1
         raise UsageError if name.blank?
 
+        puts 2
         rack = Formulary.to_rack(name.downcase)
 
+        puts 3
         dirs = rack.directory? ? rack.subdirs : []
         raise NoSuchKegError, rack.basename if dirs.empty?
 
+        puts 4
         linked_keg_ref = HOMEBREW_LINKED_KEGS/rack.basename
         opt_prefix = HOMEBREW_PREFIX/"opt/#{rack.basename}"
 
+        puts 5
         begin
           if opt_prefix.symlink? && opt_prefix.directory?
             Keg.new(opt_prefix.resolved_path)
@@ -271,7 +276,7 @@ module Homebrew
             end
 
             unless (prefix = f.installed_prefix).directory?
-              raise MultipleVersionsInstalledError, rack.basename
+              raise MultipleVersionsInstalledError, "#{rack.basename} has multiple installed versions"
             end
 
             Keg.new(prefix)

Library/Homebrew/exceptions.rb

@@ -29,14 +29,7 @@ class KegUnspecifiedError < UsageError
   end
 end
 
-class MultipleVersionsInstalledError < RuntimeError
-  attr_reader :name
-
-  def initialize(name)
-    @name = name
-    super "#{name} has multiple installed versions"
-  end
-end
+class MultipleVersionsInstalledError < RuntimeError; end
 
 class NotAKegError < RuntimeError; end
 

Library/Homebrew/test/exceptions_spec.rb

@@ -3,7 +3,7 @@
 require "exceptions"
 
 describe MultipleVersionsInstalledError do
-  subject { described_class.new("foo") }
+  subject { described_class.new("foo has multiple installed versions") }
 
   its(:to_s) { is_expected.to eq("foo has multiple installed versions") }
 end