diff -r d61cd2e5889a -r 9d047a9c76b5 SConstruct
--- a/SConstruct	Thu Mar 03 02:40:29 2011 -0800
+++ b/SConstruct	Thu Mar 03 02:43:16 2011 -0800
@@ -152,6 +152,8 @@
             help='Override which build_opts file to use for defaults')
 AddM5Option('--ignore-style', dest='ignore_style', action='store_true',
             help='Disable style checking hooks')
+AddM5Option('--print-build-vars', dest='print_build_vars', action='store_true',
+            help='Print information about the build variables')
 AddM5Option('--update-ref', dest='update_ref', action='store_true',
             help='Update test reference outputs')
 AddM5Option('--verbose', dest='verbose', action='store_true',
@@ -1040,15 +1042,24 @@
                    variant_dir = joinpath(variant_path, 'tests', e.Label),
                    exports = { 'env' : e }, duplicate = False)
 
-# base help text
-Help('''
+basic_help = '''
 Usage: scons [scons options] [build variables] [target(s)]
 
 Extra scons options:
 %(options)s
+''' % help_texts
 
+build_var_help = '''
 Global build variables:
 %(global_vars)s
 
 %(local_vars)s
-''' % help_texts)
+''' % help_texts
+
+if GetOption('print_build_vars'):
+    # Force the 'help' option so scons will print the build variables and
+    # exit.
+    SetOption('help', True)
+    Help(build_var_help)
+else:
+    Help(basic_help)