PhantomJS itself also needs to be build in debug mode.

https://code.google.com/p/phantomjs/issues/detail?id=599

build.sh

@@ -35,6 +35,10 @@ until [ -z "$1" ]; do
             shift
             QT_CFG=" $1"
             shift;;
+        "--qmake-args")
+            shift
+            QMAKE_ARGS=$1
+            shift;;
         "--jobs")
             shift
             COMPILE_JOBS=$1
@@ -54,5 +58,5 @@ until [ -z "$1" ]; do
 done
 
 cd src/qt && ./preconfig.sh --jobs $COMPILE_JOBS --qt-config "$QT_CFG" && cd ../..
-src/qt/bin/qmake
+src/qt/bin/qmake $QMAKE_ARGS
 make -j$COMPILE_JOBS

deploy/build-and-package.sh

@@ -9,7 +9,7 @@ echo "    $ make clean && cd src/qt && make clean && cd ../.."
 echo
 
 # Build the project
-./build.sh --qt-config "-debug -webkit-debug" || exit 1
+./build.sh --qt-config "-debug -webkit-debug" --qmake-args "CONFIG-=release CONFIG+=debug" || exit 1
 
 # Package the release tarball
 rm deploy/*.tar.bz2 2>/dev/null