Makefile文件报错,就随便打印一句话就报错

文件:Makefile

PROJECT_NAME:=test
ifneq (,$(findstring $(PROJECT_NAME), test))
    $(warning "1 result $(PROJECT_NAME)")
else ifneq (,$(findstring $(PROJECT_NAME), test2))
    $(warning "2 result $(PROJECT_NAME)")
else
    $(warning "3 result $(PROJECT_NAME)")
endif

运行make
打印出来是:

Makefile:4: "1 result test"
make: *** No targets.  Stop.

为什么会爆出 *** No targets. Stop.错误

https://blog.csdn.net/pendle/article/details/5870872