-# Now follow the pieces of boilerplate
-# The "-" signs tell make not to complain if they don't exist
+# When using $(patsubst ...) and friends, you can't use a literal comma
+# freely - so we use ${comma} instead. (See PACKAGE_CPP_OPTS in package.mk
+# for an example usage.)
+comma=,
+
+# -----------------------------------------------------------------------------
+# Now follow the pieces of boilerplate
+# The "-" signs tell make not to complain if they don't exist