[4/977] including MINE/my_i2c_utils/Android.mk ...
build/make/core/base_rules.mk:139: warning: *** Module name: my_i2c
build/make/core/base_rules.mk:140: warning: *** Makefile location: MINE/my_i2c_utils/Android.mk
build/make/core/base_rules.mk:141: warning: * 
build/make/core/base_rules.mk:142: warning: * Module is attempting to use the 'user' tag.  This
build/make/core/base_rules.mk:143: warning: * used to cause the module to be installed automatically.
build/make/core/base_rules.mk:144: warning: * Now, the module must be listed in the PRODUCT_PACKAGES
build/make/core/base_rules.mk:145: warning: * section of a product makefile to have it installed.
build/make/core/base_rules.mk:146: warning: * 
build/make/core/base_rules.mk:147: error: user tag detected on module..

如果再 MINE/my_i2c_utils/Android.mk 中加入 PRODUCT_PACKAGES += ..
會抱怨說 PRODUCT_PACKAGES 是 read only variable..