Fix a mismatch between our use of a sandbox while installing and
rubygems' assumptions on where to find already installed gems.

diff -ru a/lib/rubygems/commands/install_command.rb b/lib/rubygems/commands/install_command.rb
--- a/lib/rubygems/commands/install_command.rb	2008-09-11 01:54:41.000000000 +0200
+++ b/lib/rubygems/commands/install_command.rb	2008-09-28 10:24:27.000000000 +0200
@@ -76,6 +76,7 @@
       :wrappers => options[:wrappers],
       :bin_dir => options[:bin_dir],
       :development => options[:development],
+      :sandbox_fix => options[:sandbox_fix],
     }
 
     exit_code = 0
diff -ru a/lib/rubygems/dependency_installer.rb b/lib/rubygems/dependency_installer.rb
--- a/lib/rubygems/dependency_installer.rb	2008-08-12 23:50:22.000000000 +0200
+++ b/lib/rubygems/dependency_installer.rb	2008-09-28 10:22:21.000000000 +0200
@@ -40,9 +40,10 @@
   # :security_policy:: See Gem::Installer::new and Gem::Security.
   # :user_install:: See Gem::Installer.new
   # :wrappers:: See Gem::Installer::new
+  # :sandbox_fix:: Gentoo patch to repair compatibility
 
   def initialize(options = {})
-    if options[:install_dir] then
+    if options[:install_dir] and not options[:sandbox_fix] then
       spec_dir = options[:install_dir], 'specifications'
       @source_index = Gem::SourceIndex.from_gems_in spec_dir
     else
diff -ru a/lib/rubygems/install_update_options.rb b/lib/rubygems/install_update_options.rb
--- a/lib/rubygems/install_update_options.rb	2008-06-24 20:56:30.000000000 +0200
+++ b/lib/rubygems/install_update_options.rb	2008-09-28 10:24:09.000000000 +0200
@@ -83,6 +83,11 @@
       options[:include_dependencies] = value
     end
 
+    add_option(:"Install/Update", '--sandbox-fix',
+               'Fix specifications lookup path [Gentoo patch]') do |value, options|
+      options[:sandbox_fix] = true
+    end
+
     add_option(:"Install/Update",       '--[no-]format-executable',
                'Make installed executable names match ruby.',
                'If ruby is ruby18, foo_exec will be',