--- a/dev/Vagrantfile	Fri Mar 14 03:08:58 2014 +0100
+++ b/dev/Vagrantfile	Fri Mar 14 10:03:37 2014 +0100
@@ -3,7 +3,7 @@
 
 require 'yaml'
 
-custom_file_path = File.join(__dir__, 'custom.yaml')
+custom_file_path = File.join(__dir__, (ENV['SYSCONFIG'] || 'custom.yaml'))
 
 context = File.exist?(custom_file_path)?YAML::load_file(custom_file_path):{}