diff --git a/Library/Homebrew/formula_installer.rb b/Library/Homebrew/formula_installer.rb
index 808f5c1621..2a3724c195 100644
--- a/Library/Homebrew/formula_installer.rb
+++ b/Library/Homebrew/formula_installer.rb
@@ -321,16 +321,12 @@ class FormulaInstaller
 
   ## checks
 
-  def paths
-    @paths ||= ENV['PATH'].split(':').map{ |p| File.expand_path p }
-  end
-
   def check_PATH
     # warn the user if stuff was installed outside of their PATH
     [f.bin, f.sbin].each do |bin|
       if bin.directory? and bin.children.length > 0
-        bin = (HOMEBREW_PREFIX/bin.basename).realpath.to_s
-        unless paths.include? bin
+        bin = (HOMEBREW_PREFIX/bin.basename).realpath
+        unless ORIGINAL_PATHS.include? bin
           opoo "#{bin} is not in your PATH"
           puts "You can amend this by altering your ~/.bashrc file"
           @show_summary_heading = true
@@ -341,7 +337,7 @@ class FormulaInstaller
 
   def check_manpages
     # Check for man pages that aren't in share/man
-    if (f.prefix+'man').exist?
+    if (f.prefix+'man').directory?
       opoo 'A top-level "man" directory was found.'
       puts "Homebrew requires that man pages live under share."
       puts 'This can often be fixed by passing "--mandir=#{man}" to configure.'
@@ -351,7 +347,7 @@ class FormulaInstaller
 
   def check_infopages
     # Check for info pages that aren't in share/info
-    if (f.prefix+'info').exist?
+    if (f.prefix+'info').directory?
       opoo 'A top-level "info" directory was found.'
       puts "Homebrew suggests that info pages live under share."
       puts 'This can often be fixed by passing "--infodir=#{info}" to configure.'
@@ -360,7 +356,7 @@ class FormulaInstaller
   end
 
   def check_jars
-    return unless File.exist? f.lib
+    return unless f.lib.directory?
 
     jars = f.lib.children.select{|g| g.to_s =~ /\.jar$/}
     unless jars.empty?
@@ -376,7 +372,7 @@ class FormulaInstaller
   end
 
   def check_non_libraries
-    return unless File.exist? f.lib
+    return unless f.lib.directory?
 
     valid_extensions = %w(.a .dylib .framework .jnilib .la .o .so
                           .jar .prl .pm)
@@ -395,9 +391,9 @@ class FormulaInstaller
   end
 
   def audit_bin
-    return unless File.exist? f.bin
+    return unless f.bin.directory?
 
-    non_exes = f.bin.children.select {|g| File.directory? g or not File.executable? g}
+    non_exes = f.bin.children.select { |g| g.directory? or not g.executable? }
 
     unless non_exes.empty?
       opoo 'Non-executables were installed to "bin".'
@@ -409,9 +405,9 @@ class FormulaInstaller
   end
 
   def audit_sbin
-    return unless File.exist? f.sbin
+    return unless f.sbin.directory?
 
-    non_exes = f.sbin.children.select {|g| File.directory? g or not File.executable? g}
+    non_exes = f.sbin.children.select { |g| g.directory? or not g.executable? }
 
     unless non_exes.empty?
       opoo 'Non-executables were installed to "sbin".'
@@ -429,7 +425,7 @@ class FormulaInstaller
 
   def check_m4
     # Newer versions of Xcode don't come with autotools
-    return if MacOS::Xcode.version.to_f >= 4.3
+    return unless MacOS::Xcode.provides_autotools?
 
     # If the user has added our path to dirlist, don't complain
     return if File.open("/usr/share/aclocal/dirlist") do |dirlist|
diff --git a/Library/Homebrew/global.rb b/Library/Homebrew/global.rb
index d8faef0770..12157b0c04 100644
--- a/Library/Homebrew/global.rb
+++ b/Library/Homebrew/global.rb
@@ -91,4 +91,4 @@ unless ARGV.include? "--no-compat" or ENV['HOMEBREW_NO_COMPAT']
   require 'compatibility'
 end
 
-ORIGINAL_PATHS = ENV['PATH'].split(':').map{ |p| Pathname.new(File.expand_path(p)) rescue nil }.compact.freeze
+ORIGINAL_PATHS = ENV['PATH'].split(':').map{ |p| Pathname.new(p).expand_path rescue nil }.compact.freeze