The installer requires cpio of busybox to work properly.
$(MKBOOTFS) $(TARGET_INSTALLER_OUT) | gzip -9 > $@
INSTALL_RAMDISK := $(PRODUCT_OUT)/install.img
-$(INSTALL_RAMDISK): $(wildcard $(LOCAL_PATH)/install/*/*) | $(MKBOOTFS)
+$(INSTALL_RAMDISK): $(wildcard $(LOCAL_PATH)/install/*/*) | $(MKBOOTFS) $(TARGET_OUT_OPTIONAL_EXECUTABLES)/busybox
$(if $(TARGET_INSTALL_SCRIPTS),$(ACP) -p $(TARGET_INSTALL_SCRIPTS) $(TARGET_INSTALLER_OUT)/scripts)
$(MKBOOTFS) $(dir $(dir $(<D))) | gzip -9 > $@