Bug 1382511 - Add --output-sync=line to MOZ_MAKE_FLAGS where available. r=glandium

MozReview-Commit-ID: 27FK7x0NcHR

--HG--
extra : rebase_source : 5fbe0443c84e33f12ce917165762591a0cb1f213

client.mk

@@ -142,6 +142,9 @@ ifeq (,$(findstring -j,$(MOZ_MAKE_FLAGS)))
   MOZ_MAKE_FLAGS += -j$(cores)
 endif
 
+ifeq (4.0,$(firstword $(sort 4.0 $(MAKE_VERSION))))
+MOZ_MAKE_FLAGS += --output-sync=line
+endif
 
 ifdef MOZ_BUILD_PROJECTS