diff --git a/INSTALL.md b/INSTALL.md
index 0776a6f72..d27004dbd 100644
--- a/INSTALL.md
+++ b/INSTALL.md
@@ -2,6 +2,13 @@
 
 Mapnik runs on Linux, OS X, Windows, and BSD systems.
 
+First clone mapnik from github and initialize submodules
+
+```bash
+git clone https://github.com/mapnik/mapnik.git
+git submodule update --init
+```
+
 To configure and build Mapnik do:
 
 ```bash
@@ -35,7 +42,6 @@ NOTE: the above will not work on windows, rather see https://github.com/mapnik/m
 
 Then to run the tests locally (without needing to install):
 
-    git submodule update --init
     make test
 
 Install like:
diff --git a/bootstrap.sh b/bootstrap.sh
index f7cd9bd19..01e368c56 100644
--- a/bootstrap.sh
+++ b/bootstrap.sh
@@ -89,8 +89,11 @@ function make_config() {
     fi
 
     echo "
-CXX = '$CXX'
-CC = '$CC'
+CXX = '/opt/llvm/bin/clang++ -fsanitize=address -I/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/include/c++/v1/'
+CC = '/opt/llvm/bin/clang -fsanitize=address'
+CUSTOM_CXXFLAGS = '--coverage'
+CUSTOM_LDFLAGS = '--coverage'
+DEBUG = True
 RUNTIME_LINK = 'static'
 INPUT_PLUGINS = 'all'
 PATH = '${MASON_LINKED_REL}/bin'