gallium: Update scons instructions. Propagate user environment.
diff --git a/SConstruct b/SConstruct
index 01732b0..47f9b53 100644
--- a/SConstruct
+++ b/SConstruct
@@ -11,7 +11,7 @@
#
# For example, invoke scons as
#
-# scons debug=1 dri=0 x86=1
+# scons debug=1 dri=0 machine=x86
#
# to set configuration variables. Or you can write those options to a file
# named config.py:
@@ -19,7 +19,7 @@
# # config.py
# debug=1
# dri=0
-# x86=1
+# machine='x86'
#
# Invoke
#
@@ -35,7 +35,9 @@
opts.Add(EnumOption('machine', 'use machine-specific assembly code', 'x86',
allowed_values=('generic', 'x86', 'x86-64')))
-env = Environment(options = opts)
+env = Environment(
+ options = opts,
+ ENV = os.environ)
Help(opts.GenerateHelpText(env))
# for debugging