Fix native extension compilation on Phusion Passenger Standalone

lib/phusion_passenger/native_support.rb

@@ -107,7 +107,7 @@ def load_from_home_dir
 	def compile_and_load
 		STDERR.puts "*** Phusion Passenger: no #{library_name} found for " +
 			"the current Ruby interpreter. Compiling one..."
-		
+
 		require 'fileutils'
 		require 'phusion_passenger/platform_info/ruby'
 
@@ -163,6 +163,18 @@ def compile(target_dirs)
 						"trying a different directory..."
 					STDERR.puts "-------------------------------"
 				end
+			rescue Errno::ENOTDIR
+				# This can occur when PhusionPassenger.source_root
+				# is a location configuration file, and natively_packaged
+				# is set to false. For example, when we're running
+				# in Phusion Passenger Standalone. In this case
+				# just ignore this directory.
+				if i == target_dirs.size - 1
+					raise
+				else
+					STDERR.puts "Not a valid directory. Trying a different one..."
+					STDERR.puts "-------------------------------"
+				end
 			end
 		end
 		return result