# Find any prerequisites that is newer than target or that does not exist.
 # PHONY targets skipped in both cases.
-any-prereq = $(filter-out $(PHONY),$?) $(filter-out $(PHONY) $(wildcard $^),$^)
+any-prereq = $(filter-out $(PHONY),$?)$(filter-out $(PHONY) $(wildcard $^),$^)
 
 # Execute command if command has changed or prerequisite(s) are updated.
 if_changed = $(if $(strip $(any-prereq) $(cmd-check)),                       \
 why =                                                                        \
     $(if $(filter $@, $(PHONY)),- due to target is PHONY,                    \
         $(if $(wildcard $@),                                                 \
-            $(if $(strip $(any-prereq)),- due to: $(any-prereq),             \
+            $(if $(any-prereq),- due to: $(any-prereq),                      \
                 $(if $(cmd-check),                                           \
                     $(if $(cmd_$@),- due to command line change,             \
                         $(if $(filter $@, $(targets)),                       \