项目模块新增加一个module 或 buildType的时候，出现如下问题：

/Users/chrisding/iCourt/Work/Android/alpha_android_2.0/alpha/build.gradle
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :alpha_provider.
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :component_architecture.
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :component_api.
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :component_ui.
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :lib_guideview.
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :lib_daemon.
Error:Unable to resolve dependency for ':alpha@release_abc/compileClasspath': Could not resolve project :lib_calendar.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :alpha_provider.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :component_architecture.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :component_api.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :component_ui.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :lib_guideview.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :lib_daemon.
Error:Unable to resolve dependency for ':alpha@release_abcUnitTest/compileClasspath': Could not resolve project :lib_calendar.

这个是3.0的新特性：module a 依赖module b, 那么b和a的 buildType必须全部一致。

module a:

buildTypes {
    release {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
    preRelease {
        minifyEnabled false
        proguardFiles getDefaultProguardFile('proguard-android.txt'), 'proguard-rules.pro'
    }
}

module b:

buildTypes {
    release {
        minifyEnabled false
    }
    preRelease {
        minifyEnabled false
    }
}

后来我发现这样解决有坑：如果我项目里有多个可运行module，都依赖了library b呢？那岂不是所有的都这么写这么多，多不优雅！网上查了一下，有人也遇到了相同的问题，解决方式如下：
module b:

buildTypes {
    release {
        minifyEnabled false
        matchingFallbacks ['release']
    }
    preTest {
        minifyEnabled false
        matchingFallbacks ['release']
    }
}

这种方案，可以使library的buildType区别与被依赖的module的buildType，避免依赖类型必须一致的尴尬问题。当然fallback不能瞎写，只能写当前已有的buildType，是个数组，可以填多个。
亲测有效。