Merge "Add notes on using ccache"
diff --git a/src/source/building.md b/src/source/building.md
index de3bec8..5bfdee7 100644
--- a/src/source/building.md
+++ b/src/source/building.md
@@ -98,6 +98,20 @@
$ emulator
+# Using ccache #
+
+ccache is a compiler cache for C and C++ that can help make builds faster.
+In the root of the source tree, do the following:
+
+ $ export USE_CCACHE=1
+ $ export CCACHE_DIR=/<path_of_your_choice>/.ccache
+ $ prebuilt/linux-x86/ccache/ccache -M 20G
+
+You can watch ccache being used by doing the following:
+
+ $ watch -n1 -d prebuilt/linux-x86/ccache/ccache -s
+
+On OSX, you should replace `linux-x86` with `darwin-x86`.
# Troubleshooting Common Build Errors #