Make Superenv activation explicit

Library/Homebrew/build.rb

@@ -34,6 +34,7 @@ def main
 
   require 'hardware'
   require 'keg'
+  require 'superenv'
 
   # Force any future invocations of sudo to require the user's password to be
   # re-entered. This is in-case any build script call sudo. Certainly this is
@@ -106,7 +107,8 @@ class Build
     keg_only_deps = deps.map(&:to_formula).select(&:keg_only?)
 
     pre_superenv_hacks
-    require 'superenv'
+
+    ENV.activate_extensions!
 
     deps.map(&:to_formula).each do |dep|
       opt = HOMEBREW_PREFIX/:opt/dep

Library/Homebrew/cmd/--env.rb

@@ -3,6 +3,8 @@ require 'hardware'
 
 module Homebrew extend self
   def __env
+    ENV.activate_extensions!
+
     if superenv?
       ENV.deps = ARGV.formulae.map(&:name) unless ARGV.named.empty?
     end

Library/Homebrew/cmd/sh.rb

@@ -3,6 +3,8 @@ require 'formula'
 
 module Homebrew extend self
   def sh
+    ENV.activate_extensions!
+
     if superenv?
       ENV.x11 = true
       ENV.deps = Formula.installed.select{|f| f.keg_only? and f.opt_prefix.directory? }.map(&:name)

Library/Homebrew/superenv.rb

@@ -18,6 +18,19 @@ def superenv?
   true
 end
 
+module EnvActivation
+  def activate_extensions!
+    if superenv?
+      extend(Superenv)
+    else
+      extend(HomebrewEnvExtension)
+      prepend 'PATH', "#{HOMEBREW_PREFIX}/bin", ':' unless ORIGINAL_PATHS.include? HOMEBREW_PREFIX/'bin'
+    end
+  end
+end
+
+ENV.extend(EnvActivation)
+
 module Superenv
   attr_accessor :keg_only_deps, :deps, :x11
   alias_method :x11?, :x11
@@ -310,15 +323,6 @@ module Superenv
 end
 
 
-if not superenv?
-  ENV.extend(HomebrewEnvExtension)
-  # we must do this or tools like pkg-config won't get found by configure scripts etc.
-  ENV.prepend 'PATH', "#{HOMEBREW_PREFIX}/bin", ':' unless ORIGINAL_PATHS.include? HOMEBREW_PREFIX/'bin'
-else
-  ENV.extend(Superenv)
-end
-
-
 class Array
   def to_path_s
     map(&:to_s).uniq.select{|s| File.directory? s }.join(':').chuzzle