=== modified file 'debian/rules'
--- debian/rules	2016-06-23 19:46:41 +0000
+++ debian/rules	2018-02-08 12:10:21 +0000
@@ -1,4 +1,14 @@
 #!/usr/bin/make -f
+
+ifeq (,$(filter noopt,$(DEB_BUILD_OPTIONS)))
+    MAKEFLAGS += OPTIMIZE=-O0
+endif
+
+ifneq (,$(filter parallel=%,$(DEB_BUILD_OPTIONS)))
+    NUMJOBS = $(patsubst parallel=%,%,$(filter parallel=%,$(DEB_BUILD_OPTIONS)))
+    MAKEFLAGS += -j$(NUMJOBS)
+endif
+
 %:
 	dh $@