Android Studio编译时Error: app:transformClassesAndResourcesWithProguardFor 的解决

最近在弄Android Studio的Gradle文件，发现自己的项目有个地方一直编译不过去，报的错误如下：

Warning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.Response$BuilderWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.HeadersWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.ResponseBodyWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.Response$BuilderWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.ResponseBodyWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.ResponseWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.Response$BuilderWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.ResponseWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.Response$BuilderWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.ResponseWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.Response$BuilderWarning:io.bugtags.agent.instrumentation.okhttp3.ResponseBuilderExtension: can't find referenced class okhttp3.ResponseWarning:there were 528 unresolved references to classes or interfaces.Warning:Exception while processing task java.io.IOException: Please correct the above warnings first.Error:Execution failed for task ':app:transformClassesAndResourcesWithProguardForDfy_dev_Release'.> java.io.IOException: Please correct the above warnings first.Information:BUILD FAILEDInformation:Total time: 1 mins 22.716 secsInformation:1 errorInformation:278 warningsInformation:See complete output in console

可以看到错误是出在app:transformClassesAndResourcesWithProguard阶段，也就是Proguard混淆可能出现了问题。同时从上面的logcat可以看出，错误的地方应该是bugtags下面相应的逻辑。
bugtags是一个捕捉bug的sdk，那么在它的文档里应该在proguard-rules.pro有相应的配置，那么找到配置，如下：

# ProGuard configurations for Bugtags-keepattributes LineNumberTable,SourceFile-keep class com.bugtags.library.** {*;}-dontwarn org.apache.http.**-dontwarn android.net.http.AndroidHttpClient-dontwarn com.bugtags.library.**# End Bugtags

那么经过查阅资料，改为下面的代码可以通过编译：

# ProGuard configurations for Bugtags-keepattributes LineNumberTable,SourceFile-keep class com.bugtags.library.** {*;}-keep class io.bugtags.** {*;}-dontwarn io.bugtags.**-dontwarn org.apache.http.**-dontwarn android.net.http.AndroidHttpClient-dontwarn com.bugtags.library.**# End Bugtags

可以看到，加了中间的两行：

-keep class io.bugtags.** {*;}-dontwarn io.bugtags.**

这两行代码可以保证我们的应用编译通过，而不会导致出现由于库找不到而产生的崩溃性bug。
gradle文件和我们所加的第三方库经常会有一些冲突，上面的问题可能只是其中一种情况。如果大家对我的解决方法有什么建议的话，希望提出来。