Report empty list when no *.beam exists

erlang.mk

@@ -52,7 +52,7 @@ clean-all: clean clean-deps clean-docs
 	$(gen_verbose) rm -rf .$(PROJECT).plt $(DEPS_DIR) logs
 
 app: ebin/$(PROJECT).app
-	$(eval MODULES := $(shell ls ebin/*.beam \
+	$(eval MODULES := $(shell find ebin -name \*.beam \
 		| sed 's/ebin\///;s/\.beam/,/' | sed '$$s/.$$//'))
 	$(appsrc_verbose) cat src/$(PROJECT).app.src \
 		| sed 's/{modules, \[\]}/{modules, \[$(MODULES)\]}/' \