java.lang.RuntimeException: Annotation processors must be explicitly declared now.

Android Studio升級到最新版3.0 Canary 8后，當使用到注解時，報了如下錯誤：
Error:Execution failed for task ':app:javaPreCompileDebug'. > Annotation processors must be explicitly declared now. The following dependencies on the compile classpath are found to contain annotation processor. Please add them to the annotationProcessor configuration

解決辦法：在Gradle中添加如下代碼

android {
    ...
    
    defaultConfig {
        ...

        javaCompileOptions { 
            annotationProcessorOptions { 
                includeCompileClasspath = true 
            } 
        }
    }
    
    ...
}

且保證多module只有一個依賴了butterknife注解庫