all:
        @: $(MAKE); $(unstage)
        +@r=`${PWD_COMMAND}`; export r; \  <------ This is the line.
        s=`cd $(srcdir); ${PWD_COMMAND}`; export s; \
          $(MAKE) $(RECURSE_FLAGS_TO_PASS) \
                $(PGO_BUILD_GEN_FLAGS_TO_PASS) all-host all-target \
        && :