Copy CocoaDebug.framework to the root directory of your project in Finder.

Select the Build Settings tab and add the following to the Debug configuration of the Framework Search Paths (FRAMEWORK_SEARCH_PATHS) setting:

$(inherited) $(SRCROOT)

Still in the Build Settings tab, add the following to the Debug configuration of the Other Linker Flags (OTHER_LDFLAGS) setting:

-ObjC -weak_framework CocoaDebug

Still in the Build Settings tab, add the following to the Debug configuration of the Runpath Search Paths (LD_RUNPATH_SEARCH_PATHS) if it is not already present:

$(inherited) @executable_path/Frameworks

Select the Build Phases tab and add a new Run Script phase. Paste in the following shell script:

export CocoaDebug_FILENAME="CocoaDebug.framework"
export CocoaDebug_PATH="${SRCROOT}/${CocoaDebug_FILENAME}"

[ "${CONFIGURATION}" != "Debug" ] && exit 0

if [ -d "${CocoaDebug_PATH}" ]; then
"${CocoaDebug_PATH}/copy_and_codesign.sh"
fi