From dbaac79f175ca4c49082e5234e1c1d2914464076 Mon Sep 17 00:00:00 2001
From: Samuel John <github@SamuelJohn.de>
Date: Tue, 3 Sep 2013 10:41:54 +0200
Subject: [PATCH] PythonInstalled: Adding a private_site_packages

that live in the `libexec` dir of a `Cellar`.
---
 Library/Homebrew/python_helper.rb                 | 15 ++++++++-------
 .../Homebrew/requirements/python_dependency.rb    |  2 ++
 2 files changed, 10 insertions(+), 7 deletions(-)

diff --git a/Library/Homebrew/python_helper.rb b/Library/Homebrew/python_helper.rb
index bccdb7a4ec..8ebf0b7943 100644
--- a/Library/Homebrew/python_helper.rb
+++ b/Library/Homebrew/python_helper.rb
@@ -51,22 +51,22 @@ def python_helper(options={:allowed_major_versions => [2, 3]}, &block)
   filtered_python_reqs.sort_by{ |py| py.version }.map do |py|
     # Now is the time to `site_packages` to the correct value in the Cellar.
     py.site_packages = lib/py.xy/'site-packages'
+    py.private_site_packages = libexec/"lib"/py.xy/"site-packages"
     return py if !block_given?
 
     puts "brew: Python block (#{py.binary})..." if ARGV.verbose? && ARGV.debug?
-    # Ensure env changes are only temporary
     # Ensure env changes are only temporary:
     begin
       old_env = ENV.to_hash
-      # In order to install into the Cellar, the dir must exist and be in the
-      # PYTHONPATH. This will be executed in the context of the formula
-      # so that lib points to the HOMEBREW_PREFIX/Cellar/<formula>/<version>/lib
-      puts "brew: setting PYTHONPATH to: #{py.site_packages}" if ARGV.verbose?
       # In order to install into the `Cellar`, the dir must exist and be in the
       # `PYTHONPATH`. This will be executed in the context of the formula and
       # lib points to the `HOMEBREW_PREFIX/Cellar/<formula>/<version>/lib`.
       mkdir_p py.site_packages
-      ENV['PYTHONPATH'] = py.site_packages
+      ENV.append_path 'PYTHONPATH', py.site_packages
+      # Allow to --prefix=libexec if a private site-packages is needed.
+      mkdir_p py.private_site_packages
+      ENV.append_path 'PYTHONPATH', py.private_site_packages
+      puts "brew: PYTHONPATH=#{ENV['PYTHONPATH']}" if ARGV.verbose?
       ENV['PYTHON'] = py.binary
       ENV.prepend_path 'CMAKE_INCLUDE_PATH', py.incdir
       ENV.prepend_path 'PKG_CONFIG_PATH', py.pkg_config_path if py.pkg_config_path
@@ -76,13 +76,14 @@ def python_helper(options={:allowed_major_versions => [2, 3]}, &block)
 
       # Track the state of the currently selected python for this block,
       # so if this python_helper is called again _inside_ the block,
-      # we can just return the right python
       # we can just return the right python.
       @current_python = py
       res = instance_eval(&block)
       @current_python = nil
       res
     ensure
+      # Clean up if the private_site_packages has not been used.
+      py.private_site_packages.rmdir if py.private_site_packages.children.empty?
       ENV.replace(old_env)
     end
   end
diff --git a/Library/Homebrew/requirements/python_dependency.rb b/Library/Homebrew/requirements/python_dependency.rb
index 490a8f3c16..a647527668 100644
--- a/Library/Homebrew/requirements/python_dependency.rb
+++ b/Library/Homebrew/requirements/python_dependency.rb
@@ -19,6 +19,7 @@ class PythonInstalled < Requirement
   attr_reader :imports
   attr_reader :python
   attr_accessor :site_packages
+  attr_accessor :private_site_packages
   attr_writer :binary # The python.rb formula needs to set the binary
 
   fatal true  # you can still make Python optional by `depends_on :python => :optional`
@@ -70,6 +71,7 @@ class PythonInstalled < Requirement
     # will be set later by the python_helper, because it needs the
     # formula prefix to set site_packages
     @site_packages = nil
+    @private_site_packages = nil
 
     super tags
   end