--- old/make/HotspotWrapper.gmk	2016-01-14 11:38:04.578793667 +0100
+++ new/make/HotspotWrapper.gmk	2016-01-14 11:38:04.494790140 +0100
@@ -35,14 +35,18 @@
 
 default: all
 
-# Get all files except .hg in the hotspot directory.
-HOTSPOT_FILES := $(shell $(FIND) -L $(HOTSPOT_TOPDIR) -name ".hg" -prune -o -print)
+# Get all files in src, make or agent subdirs in hotspot directory and
+# filter out .hg. This skips the test directory.
+HOTSPOT_FILES := $(shell $(FIND) -L \
+    $(HOTSPOT_TOPDIR)/src $(HOTSPOT_TOPDIR)/make $(HOTSPOT_TOPDIR)/agent \
+    -name ".hg" -prune -o -print)
 
 # The old build creates hotspot output dir before calling hotspot and
 # not doing it breaks builds on msys.
 $(HOTSPOT_OUTPUTDIR)/_hotspot.timestamp: $(HOTSPOT_FILES)
 	@$(MKDIR) -p $(HOTSPOT_OUTPUTDIR)
-	@($(CD) $(HOTSPOT_TOPDIR)/make && $(MAKE) $(HOTSPOT_MAKE_ARGS) LOG_LEVEL=$(LOG_LEVEL) SPEC=$(HOTSPOT_SPEC) BASE_SPEC=$(BASE_SPEC))
+	@($(CD) $(HOTSPOT_TOPDIR)/make && $(MAKE) $(HOTSPOT_MAKE_ARGS) \
+	    LOG_LEVEL=$(LOG_LEVEL) SPEC=$(HOTSPOT_SPEC) BASE_SPEC=$(BASE_SPEC))
 	$(TOUCH) $@
 
 hotspot: $(HOTSPOT_OUTPUTDIR)/_hotspot.timestamp