Fix bugs in the build system

Rakefile

@@ -50,7 +50,6 @@ end
 
 desc "Remove compiled files"
 task :clean do
-	sh "rm -rf build/cache"
 	sh "rm -rf buildout"
 end
 

build/agents.rb

@@ -177,8 +177,5 @@
 end
 
 task 'common:clean' do
-	['PassengerWatchdog', 'PassengerHelperAgent', 'PassengerLoggingAgent', 'SpawnPreparer', 'EnvPrinter'].each do |agent|
-		sh "rm -rf #{AGENT_OUTPUT_DIR}#{agent} #{AGENT_OUTPUT_DIR}#{agent}.o #{AGENT_OUTPUT_DIR}#{agent}.dSYM"
-	end
-	sh "rm -rf agents"
+	sh "rm -rf #{AGENT_OUTPUT_DIR}"
 end

build/basics.rb

@@ -23,6 +23,7 @@
 
 require 'rubygems'
 require 'pathname'
+require 'fileutils'
 require 'phusion_passenger'
 PhusionPassenger.locate_directories
 require 'phusion_passenger/packaging'
@@ -110,11 +111,8 @@ def maybe_wrap_in_ccache(command)
 end
 
 if boolean_option('CACHING', true) && !boolean_option('RELEASE')
-	if OUTPUT_DIR.empty?
-		PlatformInfo.cache_dir = File.expand_path("cache", File.dirname(__FILE__))
-	else
-		PlatformInfo.cache_dir = OUTPUT_DIR + "cache"
-	end
+	PlatformInfo.cache_dir = OUTPUT_DIR + "cache"
+	FileUtils.mkdir_p(PlatformInfo.cache_dir)
 end
 
 #################################################