ionic打包报错Execution failed for task ':processDebugResources'

ionic项目打包运行命令 ionic build android的时候报错

• 报错详情如下

:processDebugResourcesERROR: In <declare-styleable> FontFamilyFont, unable to find attribute android:fontVariationSettings
ERROR: In <declare-styleable> FontFamilyFont, unable to find attribute android:ttcIndex

 FAILED

FAILURE: Build failed with an exception.

* What went wrong:
Execution failed for task ':processDebugResources'.
> com.android.ide.common.process.ProcessException: Failed to execute aapt

BUILD FAILED

Total time: 27.96 secs
* Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.
Error: cmd: Command failed with exit code 1 Error output:
ERROR: In <declare-styleable> FontFamilyFont, unable to find attribute android:fontVariationSettings
ERROR: In <declare-styleable> FontFamilyFont, unable to find attribute android:ttcIndex

FAILURE: Build failed with an exception.

 * What went wrong:
Execution failed for task ':processDebugResources'.
> com.android.ide.common.process.ProcessException: Failed to execute aapt

 * Try:
Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output.

• 解决办法：

已经执行过命令ionic cordova platform add android 添加了android平台，
直接打开目录 你的项目工程/platform/build.gradle文件中
找到def addSigningProps(propsFilePath, signingConfig){...}方法
在这个方法之前添加上如下内容

gradle.taskGraph.whenReady { taskGraph ->
    taskGraph.getAllTasks().each() { task ->
        if (task.name == 'validateReleaseSigning' || task.name == 'validateSigningRelease') {
            promptForReleaseKeyPassword()
        }
    }
}

def addSigningProps(propsFilePath, signingConfig) {
...
}

• 原因分析

compile "com.android.support:support-v4:+" 带+号是指要用最新版本。

force 'com.android.support:support-v4:27.1.0' 添加force强制指定annotations