revert the debugging changes

Building a non-optimized (-O0 vs. -O2) Debian package required:

    echo 'export DEB_BUILD_OPTIONS=noopt' >> ~/.pbuilderrc

common.mk

@@ -124,12 +124,10 @@ CPPFLAGS += -D_GNU_SOURCE
 endif
 
 ifeq ($(DEBUG),1)
-$(warning "DEBUG build")
 # Extended debugging flags, macros shall be available in gcc
 CFLAGS += -gdwarf-2
 CFLAGS += -g3
 else
-$(warning "non-DEBUG build, enabling optimization")
 CFLAGS += -O2
 CFLAGS += -freorder-blocks-and-partition
 endif
@@ -140,7 +138,7 @@ LIBS += -lgcov
 endif
 
 # Don’t print command lines which are run
-#.SILENT:
+.SILENT:
 
 # Always remake the following targets
 .PHONY: install clean dist distclean

debian/rules

@@ -28,8 +28,7 @@ binary-indep: install
 binary: binary-arch binary-indep
 
 override_dh_auto_build:
-	env
-	$(MAKE) -d
+	$(MAKE)
 	$(MAKE) -C man
 	$(MAKE) -C docs