深海游弋的鱼 – 第 84 页

解决Android Studio 3.2.1中NDK编译代码时候出现警告": warning: conflicts with previous declaration here [-Wattributes]"

在使用Android Studio 3.2.1 结合 NDK r16/r18编译代码时候出现如下警告：

<built-in>: In function 'float abs(float)':
<built-in>: warning: conflicts with previous declaration here [-Wattributes]

1 2	<built-in>: In function 'float abs(float)': <built-in>: warning: conflicts with previous declaration here [-Wattributes]

关键是出现警告的代码文件中并不一定存在abs函数的调用。

这个警告产生的条件是在编译器中指定了STL，并且指定编译器为GCC，调用的源代码文件中恰好有STL的代码。

类似如下：

externalNativeBuild {
    cmake {
        cppFlags "-DANDROID_ARM_NEON=TRUE", "-DANDROID_TOOLCHAIN=gcc", "-DANDROID_PLATFORM=android-21", "-DANDROID_STL=c++_static"
        abiFilters 'armeabi-v7a'
    }
}

externalNativeBuild {

cmake {

cppFlags "-DANDROID_ARM_NEON=TRUE", "-DANDROID_TOOLCHAIN=gcc", "-DANDROID_PLATFORM=android-21", "-DANDROID_STL=c++_static"

abiFilters 'armeabi-v7a'

}

原因在于新版本的NDK r16/r18中，对于GCC部分的适配已经不是非常完善了，已经逐步迁移到CLANG(LLVM)了。导致STL进行编译的时候，会出现一些警告信息。这个警告信息是STL库的警告信息，跟我们自己的代码没有关系。

只需要指定 "-DANDROID_TOOLCHAIN=clang" 即可解决这个问题。

参考链接

NDK r13, -fexceptions -Wall --> warning: conflicts with previous declaration

解决git clone --recursive部分失败后继续检出代码

在使用如下命令检出Vulkan的时候，发生失败，Vulkan的代码已经成功检出，但是子模块没有完成

$ git clone --recursive https://github.com/SaschaWillems/Vulkan.git

1	$ git clone --recursive https://github.com/SaschaWillems/Vulkan.git

提示的出错信息如下：

warning: 克隆成功，但是检出失败。
您可以通过 'git status' 检查哪些已被检出，然后使用命令
'git checkout -f HEAD' 重试

warning: 克隆成功，但是检出失败。

您可以通过 'git status' 检查哪些已被检出，然后使用命令

'git checkout -f HEAD' 重试

可以使用如下命令继续检出子模块：

$ git submodule update --init --recursive --progress

1	$ git submodule update --init --recursive --progress

Android Studio 3.2.1解决错误信息"No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android"

在用Android Studio 3.2.1导入以前的项目，进行编译的时候，报告如下错误信息：

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':app'.
> No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android

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

* Get more help at https://help.gradle.org

CONFIGURE FAILED in 5s
No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android

FAILURE: Build failed with an exception.

* What went wrong:

A problem occurred configuring project ':app'.

> No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android

* Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

CONFIGURE FAILED in 5s

No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android

这个错误信息的原因是从NDK r17版本开始，已经不支持"armeabi、mips、mips64"这三种ABI格式了，而当前机器上安装的NDK版本是NDK r17之后的版本。

不过这个提示很能迷惑人，会让人误以为自己的build.gradle中配置了MIPS的ABI。实际上根本没有配置，是低版本的构建工具自己在默认构建MIPS格式，而又找不到对应的工具链。

解决方法很简单，要么使用低于NDK r17的NDK版本，要么修改主工程的build.gradle,找到如下

// Top-level build file where you can add configuration options common to all sub-projects/modules.
configure(allprojects) {
    buildscript {
        repositories {
		    google()
            jcenter()
        }
        dependencies {
            classpath 'com.android.tools.build:gradle:3.0.0'
        }
    }

    repositories {
          jcenter()
    }
}

// Top-level build file where you can add configuration options common to all sub-projects/modules.

configure(allprojects) {

buildscript {

repositories {

google()

jcenter()

}

dependencies {

classpath 'com.android.tools.build:gradle:3.0.0'

}

repositories {

jcenter()

}

将其中的

classpath 'com.android.tools.build:gradle:3.0.0'

1	classpath 'com.android.tools.build:gradle:3.0.0'

修改成

classpath 'com.android.tools.build:gradle:3.2.1'

1	classpath 'com.android.tools.build:gradle:3.2.1'

高版本的构建工具，才能适配高版本的NDK。

参考链接

"No toolchains found in the NDK toolchains folder for ABI with prefix: mips64el-linux-android"

Android Studio 3.2.1解决错误信息"ABIs [armeabi] are not supported for platform. Supported ABIs are [arm64-v8a, armeabi-v7a, x86, x86_64]."

在用Android Studio 3.2.1导入以前的项目，进行编译的时候，报告如下错误信息：

FAILURE: Build failed with an exception.

* What went wrong:
A problem occurred configuring project ':app'.
> ABIs [armeabi] are not supported for platform. Supported ABIs are [arm64-v8a, armeabi-v7a, x86, x86_64].

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

* Get more help at https://help.gradle.org

BUILD FAILED in 0s

FAILURE: Build failed with an exception.

* What went wrong:

A problem occurred configuring project ':app'.

> ABIs [armeabi] are not supported for platform. Supported ABIs are [arm64-v8a, armeabi-v7a, x86, x86_64].

* Try:

Run with --stacktrace option to get the stack trace. Run with --info or --debug option to get more log output. Run with --scan to get full insights.

* Get more help at https://help.gradle.org

BUILD FAILED in 0s

问题发生的原因在于以前的代码在build.gradle中指定了abiFilters 'armeabi',但是从NDK r17版本开始，已经不支持"armeabi、mips、mips64"这三种ABI了。

虽然可以简单的修改成abiFilters 'armeabi-v7a'，来解决问题，但是我们更希望能有一个办法，在老版本的支持abiFilters 'armeabi'的NDK上继续使用abiFilters 'armeabi'进行编译，用来兼容老设备。而在只支持abiFilters 'armeabi-v7a'的设备上，我们使用abiFilters 'armeabi-v7a'保证能编译通过。

我们通过执行NDK目录下的ndk-which输出的支持的ABI列表的方式获取当前的NDK是否支持abiFilters 'armeabi'，如果不支持，我们就设置为abiFilters 'armeabi-v7a'。

继续阅读Android Studio 3.2.1解决错误信息"ABIs [armeabi] are not supported for platform. Supported ABIs are [arm64-v8a, armeabi-v7a, x86, x86_64]."

Android Studio 3.2.1在build.gradle中输出自定义日志&查看构建日志

在使用Android Studio开发Android项目的时候，我们有时候需要在build.gradle中增加一部分日志，来分析编译执行情况。

早期版本只能使用logger对象输出内容，如下：

logger.quiet('An info log message which is always logged.')
logger.error('An error log message.')
logger.warn('A warning log message.')
logger.lifecycle('A lifecycle info log message.')
logger.info('An info log message.')
logger.debug('A debug log message.')
logger.trace('A trace log message.')

logger.quiet('An info log message which is always logged.')

logger.error('An error log message.')

logger.warn('A warning log message.')

logger.lifecycle('A lifecycle info log message.')

logger.info('An info log message.')

logger.debug('A debug log message.')

logger.trace('A trace log message.')

目前最新的gradle 4.6版本已经支持println函数输出日志，如下：

println 'A message which is logged at QUIET level'

1	println 'A message which is logged at QUIET level'

只是，目前的Android Studio 3.2.1版本中，默认情况下，输出信息被简化了，导致我们找不到添加的输出内容。

只需要点击Build选项卡中的Toggle view选项，就可以看到我们的输出了。

具体操作如下图：
继续阅读Android Studio 3.2.1在build.gradle中输出自定义日志&查看构建日志

解决Android Studio 3.2.1版本在编译Vulkan时报告错误"Could not find com.android.tools.build:aapt2:3.2.1-4818971"

目前的最新Android Studio 3.2.1版本在编译Vulkan时报告错误"Could not find com.android.tools.build:aapt2:3.2.1-4818971"，详细错误信息如下：

org.gradle.api.UncheckedIOException: Failed to capture snapshot of input files for task ':examples/:radialblur:mergeDebugResources' property 'aapt2FromMaven' during up-to-date check.
	at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.snapshotTaskFiles(CacheBackedTaskHistoryRepository.java:331)
	at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.createExecution(CacheBackedTaskHistoryRepository.java:151)
	at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.access$100(CacheBackedTaskHistoryRepository.java:61)
	at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository$1.getCurrentExecution(CacheBackedTaskHistoryRepository.java:111)
	at org.gradle.api.internal.changedetection.changes.DefaultTaskArtifactStateRepository$TaskArtifactStateImpl.getStates(DefaultTaskArtifactStateRepository.java:208)
	at org.gradle.api.internal.changedetection.changes.DefaultTaskArtifactStateRepository$TaskArtifactStateImpl.isUpToDate(DefaultTaskArtifactStateRepository.java:93)
	at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:50)
	at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)
	at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)
	at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)
	at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)
	at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)
	at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)
	at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)
	at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)
	at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)
	at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)
	at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:256)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
	at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:249)
	at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:238)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)
	at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:663)
	at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:597)
	at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)
	at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)
	at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)
	at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)
	at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)
	at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)
	at java.lang.Thread.run(Thread.java:745)
Caused by: org.gradle.api.internal.artifacts.ivyservice.DefaultLenientConfiguration$ArtifactResolveException: Could not resolve all files for configuration ':examples/:radialblur:_internal_aapt2_binary'.
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.rethrowFailure(DefaultConfiguration.java:944)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.access$1600(DefaultConfiguration.java:120)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getFiles(DefaultConfiguration.java:918)
	at org.gradle.api.internal.file.AbstractFileCollection.iterator(AbstractFileCollection.java:68)
	at org.gradle.api.internal.changedetection.state.AbstractFileCollectionSnapshotter$FileCollectionVisitorImpl.visitCollection(AbstractFileCollectionSnapshotter.java:72)
	at org.gradle.api.internal.file.AbstractFileCollection.visitRootElements(AbstractFileCollection.java:234)
	at org.gradle.api.internal.file.CompositeFileCollection.visitRootElements(CompositeFileCollection.java:185)
	at org.gradle.api.internal.changedetection.state.AbstractFileCollectionSnapshotter.snapshot(AbstractFileCollectionSnapshotter.java:55)
	at org.gradle.api.internal.changedetection.state.DefaultGenericFileCollectionSnapshotter.snapshot(DefaultGenericFileCollectionSnapshotter.java:38)
	at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.snapshotTaskFiles(CacheBackedTaskHistoryRepository.java:329)
	... 36 more
Caused by: org.gradle.internal.resolve.ModuleVersionNotFoundException: Could not find com.android.tools.build:aapt2:3.2.1-4818971.
Searched in the following locations:
    file:/Users/user/Library/Android/sdk/extras/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom
    file:/Users/user/Library/Android/sdk/extras/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar
    file:/Users/user/Library/Android/sdk/extras/google/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom
    file:/Users/user/Library/Android/sdk/extras/google/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar
    file:/Users/user/Library/Android/sdk/extras/android/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom
    file:/Users/user/Library/Android/sdk/extras/android/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar
    https://jcenter.bintray.com/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom
    https://jcenter.bintray.com/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar
Required by:
    project :examples/:radialblur
	at org.gradle.internal.resolve.result.DefaultBuildableComponentResolveResult.notFound(DefaultBuildableComponentResolveResult.java:38)
	at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.RepositoryChainComponentMetaDataResolver.resolveModule(RepositoryChainComponentMetaDataResolver.java:108)
	at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.RepositoryChainComponentMetaDataResolver.resolve(RepositoryChainComponentMetaDataResolver.java:63)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.ComponentResolversChain$ComponentMetaDataResolverChain.resolve(ComponentResolversChain.java:93)
	at org.gradle.api.internal.artifacts.ivyservice.clientmodule.ClientModuleResolver.resolve(ClientModuleResolver.java:60)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.ComponentState.resolve(ComponentState.java:163)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.ComponentState.getMetaData(ComponentState.java:174)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.EdgeState.calculateTargetConfigurations(EdgeState.java:137)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.EdgeState.attachToTargetConfigurations(EdgeState.java:108)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.attachToTargetRevisionsSerially(DependencyGraphBuilder.java:236)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.resolveEdges(DependencyGraphBuilder.java:226)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.traverseGraph(DependencyGraphBuilder.java:140)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.resolve(DependencyGraphBuilder.java:111)
	at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DefaultArtifactDependencyResolver.resolve(DefaultArtifactDependencyResolver.java:92)
	at org.gradle.api.internal.artifacts.ivyservice.DefaultConfigurationResolver.resolveGraph(DefaultConfigurationResolver.java:146)
	at org.gradle.api.internal.artifacts.ivyservice.ShortCircuitEmptyConfigurationResolver.resolveGraph(ShortCircuitEmptyConfigurationResolver.java:73)
	at org.gradle.api.internal.artifacts.ivyservice.ErrorHandlingConfigurationResolver.resolveGraph(ErrorHandlingConfigurationResolver.java:66)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$4.run(DefaultConfiguration.java:494)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)
	at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveGraphIfRequired(DefaultConfiguration.java:485)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveToStateOrLater(DefaultConfiguration.java:470)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.access$1700(DefaultConfiguration.java:120)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getSelectedArtifacts(DefaultConfiguration.java:927)
	at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getFiles(DefaultConfiguration.java:915)
	... 43 more

org.gradle.api.UncheckedIOException: Failed to capture snapshot of input files for task ':examples/:radialblur:mergeDebugResources' property 'aapt2FromMaven' during up-to-date check.

at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.snapshotTaskFiles(CacheBackedTaskHistoryRepository.java:331)

at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.createExecution(CacheBackedTaskHistoryRepository.java:151)

at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.access$100(CacheBackedTaskHistoryRepository.java:61)

at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository$1.getCurrentExecution(CacheBackedTaskHistoryRepository.java:111)

at org.gradle.api.internal.changedetection.changes.DefaultTaskArtifactStateRepository$TaskArtifactStateImpl.getStates(DefaultTaskArtifactStateRepository.java:208)

at org.gradle.api.internal.changedetection.changes.DefaultTaskArtifactStateRepository$TaskArtifactStateImpl.isUpToDate(DefaultTaskArtifactStateRepository.java:93)

at org.gradle.api.internal.tasks.execution.SkipUpToDateTaskExecuter.execute(SkipUpToDateTaskExecuter.java:50)

at org.gradle.api.internal.tasks.execution.ResolveTaskOutputCachingStateExecuter.execute(ResolveTaskOutputCachingStateExecuter.java:54)

at org.gradle.api.internal.tasks.execution.ValidatingTaskExecuter.execute(ValidatingTaskExecuter.java:59)

at org.gradle.api.internal.tasks.execution.SkipEmptySourceFilesTaskExecuter.execute(SkipEmptySourceFilesTaskExecuter.java:101)

at org.gradle.api.internal.tasks.execution.FinalizeInputFilePropertiesTaskExecuter.execute(FinalizeInputFilePropertiesTaskExecuter.java:44)

at org.gradle.api.internal.tasks.execution.CleanupStaleOutputsExecuter.execute(CleanupStaleOutputsExecuter.java:91)

at org.gradle.api.internal.tasks.execution.ResolveTaskArtifactStateTaskExecuter.execute(ResolveTaskArtifactStateTaskExecuter.java:62)

at org.gradle.api.internal.tasks.execution.SkipTaskWithNoActionsExecuter.execute(SkipTaskWithNoActionsExecuter.java:59)

at org.gradle.api.internal.tasks.execution.SkipOnlyIfTaskExecuter.execute(SkipOnlyIfTaskExecuter.java:54)

at org.gradle.api.internal.tasks.execution.ExecuteAtMostOnceTaskExecuter.execute(ExecuteAtMostOnceTaskExecuter.java:43)

at org.gradle.api.internal.tasks.execution.CatchExceptionTaskExecuter.execute(CatchExceptionTaskExecuter.java:34)

at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker$1.run(DefaultTaskGraphExecuter.java:256)

at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)

at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)

at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)

at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)

at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:249)

at org.gradle.execution.taskgraph.DefaultTaskGraphExecuter$EventFiringTaskWorker.execute(DefaultTaskGraphExecuter.java:238)

at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.processTask(DefaultTaskPlanExecutor.java:123)

at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.access$200(DefaultTaskPlanExecutor.java:79)

at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:104)

at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker$1.execute(DefaultTaskPlanExecutor.java:98)

at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.execute(DefaultTaskExecutionPlan.java:663)

at org.gradle.execution.taskgraph.DefaultTaskExecutionPlan.executeWithTask(DefaultTaskExecutionPlan.java:597)

at org.gradle.execution.taskgraph.DefaultTaskPlanExecutor$TaskExecutorWorker.run(DefaultTaskPlanExecutor.java:98)

at org.gradle.internal.concurrent.ExecutorPolicy$CatchAndRecordFailures.onExecute(ExecutorPolicy.java:63)

at org.gradle.internal.concurrent.ManagedExecutorImpl$1.run(ManagedExecutorImpl.java:46)

at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1142)

at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:617)

at org.gradle.internal.concurrent.ThreadFactoryImpl$ManagedThreadRunnable.run(ThreadFactoryImpl.java:55)

at java.lang.Thread.run(Thread.java:745)

Caused by: org.gradle.api.internal.artifacts.ivyservice.DefaultLenientConfiguration$ArtifactResolveException: Could not resolve all files for configuration ':examples/:radialblur:_internal_aapt2_binary'.

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.rethrowFailure(DefaultConfiguration.java:944)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.access$1600(DefaultConfiguration.java:120)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getFiles(DefaultConfiguration.java:918)

at org.gradle.api.internal.file.AbstractFileCollection.iterator(AbstractFileCollection.java:68)

at org.gradle.api.internal.changedetection.state.AbstractFileCollectionSnapshotter$FileCollectionVisitorImpl.visitCollection(AbstractFileCollectionSnapshotter.java:72)

at org.gradle.api.internal.file.AbstractFileCollection.visitRootElements(AbstractFileCollection.java:234)

at org.gradle.api.internal.file.CompositeFileCollection.visitRootElements(CompositeFileCollection.java:185)

at org.gradle.api.internal.changedetection.state.AbstractFileCollectionSnapshotter.snapshot(AbstractFileCollectionSnapshotter.java:55)

at org.gradle.api.internal.changedetection.state.DefaultGenericFileCollectionSnapshotter.snapshot(DefaultGenericFileCollectionSnapshotter.java:38)

at org.gradle.api.internal.changedetection.state.CacheBackedTaskHistoryRepository.snapshotTaskFiles(CacheBackedTaskHistoryRepository.java:329)

... 36 more

Caused by: org.gradle.internal.resolve.ModuleVersionNotFoundException: Could not find com.android.tools.build:aapt2:3.2.1-4818971.

Searched in the following locations:

file:/Users/user/Library/Android/sdk/extras/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom

file:/Users/user/Library/Android/sdk/extras/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar

file:/Users/user/Library/Android/sdk/extras/google/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom

file:/Users/user/Library/Android/sdk/extras/google/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar

file:/Users/user/Library/Android/sdk/extras/android/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom

file:/Users/user/Library/Android/sdk/extras/android/m2repository/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar

https://jcenter.bintray.com/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971.pom

https://jcenter.bintray.com/com/android/tools/build/aapt2/3.2.1-4818971/aapt2-3.2.1-4818971-osx.jar

Required by:

project :examples/:radialblur

at org.gradle.internal.resolve.result.DefaultBuildableComponentResolveResult.notFound(DefaultBuildableComponentResolveResult.java:38)

at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.RepositoryChainComponentMetaDataResolver.resolveModule(RepositoryChainComponentMetaDataResolver.java:108)

at org.gradle.api.internal.artifacts.ivyservice.ivyresolve.RepositoryChainComponentMetaDataResolver.resolve(RepositoryChainComponentMetaDataResolver.java:63)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.ComponentResolversChain$ComponentMetaDataResolverChain.resolve(ComponentResolversChain.java:93)

at org.gradle.api.internal.artifacts.ivyservice.clientmodule.ClientModuleResolver.resolve(ClientModuleResolver.java:60)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.ComponentState.resolve(ComponentState.java:163)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.ComponentState.getMetaData(ComponentState.java:174)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.EdgeState.calculateTargetConfigurations(EdgeState.java:137)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.EdgeState.attachToTargetConfigurations(EdgeState.java:108)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.attachToTargetRevisionsSerially(DependencyGraphBuilder.java:236)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.resolveEdges(DependencyGraphBuilder.java:226)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.traverseGraph(DependencyGraphBuilder.java:140)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.graph.builder.DependencyGraphBuilder.resolve(DependencyGraphBuilder.java:111)

at org.gradle.api.internal.artifacts.ivyservice.resolveengine.DefaultArtifactDependencyResolver.resolve(DefaultArtifactDependencyResolver.java:92)

at org.gradle.api.internal.artifacts.ivyservice.DefaultConfigurationResolver.resolveGraph(DefaultConfigurationResolver.java:146)

at org.gradle.api.internal.artifacts.ivyservice.ShortCircuitEmptyConfigurationResolver.resolveGraph(ShortCircuitEmptyConfigurationResolver.java:73)

at org.gradle.api.internal.artifacts.ivyservice.ErrorHandlingConfigurationResolver.resolveGraph(ErrorHandlingConfigurationResolver.java:66)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$4.run(DefaultConfiguration.java:494)

at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:336)

at org.gradle.internal.progress.DefaultBuildOperationExecutor$RunnableBuildOperationWorker.execute(DefaultBuildOperationExecutor.java:328)

at org.gradle.internal.progress.DefaultBuildOperationExecutor.execute(DefaultBuildOperationExecutor.java:199)

at org.gradle.internal.progress.DefaultBuildOperationExecutor.run(DefaultBuildOperationExecutor.java:110)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveGraphIfRequired(DefaultConfiguration.java:485)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.resolveToStateOrLater(DefaultConfiguration.java:470)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration.access$1700(DefaultConfiguration.java:120)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getSelectedArtifacts(DefaultConfiguration.java:927)

at org.gradle.api.internal.artifacts.configurations.DefaultConfiguration$ConfigurationFileCollection.getFiles(DefaultConfiguration.java:915)

... 43 more

导致问题的原因为源代码根目录下的build.gradle中缺少对于google源服务器的配置（话说，貌似以前版本的都在jcenter中可以找到，最新版本的，好像没有上传到jcenter服务器了，估计是google的商业策略了，在此不多做评述）

打开该文件里面的内容显示如下：

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.3'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        jcenter()
    }
}

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {

repositories {

google()

jcenter()

}

dependencies {

classpath 'com.android.tools.build:gradle:3.1.3'

// NOTE: Do not place your application dependencies here; they belong

// in the individual module build.gradle files

}

allprojects {

repositories {

jcenter()

}

解决方法为在allprojects字段中增加google()源服务器。

修改后的配置变更如下：

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {
    repositories {
        google()
        jcenter()
    }
    dependencies {
        classpath 'com.android.tools.build:gradle:3.1.3'
        // NOTE: Do not place your application dependencies here; they belong
        // in the individual module build.gradle files
    }
}

allprojects {
    repositories {
        google()
        jcenter()
    }
}

// Top-level build file where you can add configuration options common to all sub-projects/modules.

buildscript {

repositories {

google()

jcenter()

}

dependencies {

classpath 'com.android.tools.build:gradle:3.1.3'

// NOTE: Do not place your application dependencies here; they belong

// in the individual module build.gradle files

}

allprojects {

repositories {

google()

jcenter()

}

参考链接

Build errors after Android Studio 3.2.1 upgrade

解决ubuntu 16.04下更改MySQL的数据库位置

ubuntu 16.04下使用APT安装的MySQL的数据库，目录同时接受apparmor的管理，因此在修改数据库目录的时候，需要同步更新apparmor的配置文件。如果只是迁移数据库的话

$ sudo service mysql stop

$ sudo mv /var/lib/mysql /data/

$ sudo ln -s /data/mysql /var/lib/mysql

$ sudo cp /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/usr.sbin.mysqld.bak

# 增加数据库的访问目录权限，增加如下目录的权限
#  /data/mysql/ r,
#  /data/mysql/** rw,

$ sudo sed -i "s/^[ \t]*\/var\/lib\/mysql\/\*\* rw,/  \/var\/lib\/mysql\/** rw,\n  \/data\/mysql r,\n  \/data\/mysql\/** rwk,/g" /etc/apparmor.d/usr.sbin.mysqld

# 检查完成无误之后，需要删除备份的 usr.sbin.mysqld.bak ，老版本的 apparmor 不会解析备份的文件/或者解析顺序变更了，但是新版本的会解析，导致出现两个不同的配置同时存在，引起异常
$ sudo rm -rf /etc/apparmor.d/usr.sbin.mysqld.bak

$ sudo service apparmor restart

$ sudo service mysql start

$ sudo service mysql stop

$ sudo mv /var/lib/mysql /data/

$ sudo ln -s /data/mysql /var/lib/mysql

$ sudo cp /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/usr.sbin.mysqld.bak

# 增加数据库的访问目录权限，增加如下目录的权限

# /data/mysql/ r,

# /data/mysql/** rw,

$ sudo sed -i "s/^[ \t]*\/var\/lib\/mysql\/\*\* rw,/ \/var\/lib\/mysql\/** rw,\n \/data\/mysql r,\n \/data\/mysql\/** rwk,/g" /etc/apparmor.d/usr.sbin.mysqld

# 检查完成无误之后，需要删除备份的 usr.sbin.mysqld.bak ，老版本的 apparmor 不会解析备份的文件/或者解析顺序变更了，但是新版本的会解析，导致出现两个不同的配置同时存在，引起异常

$ sudo rm -rf /etc/apparmor.d/usr.sbin.mysqld.bak

$ sudo service apparmor restart

$ sudo service mysql start

对于日志文件一起迁移的情况

$ sudo service tomcat7 stop

$ sudo service denyhosts stop

$ sudo service php7.0-fpm stop

$ sudo service apache2 stop

$ sudo service mysql stop

$ sudo service nginx stop

$ sudo service apparmor stop

$ sudo mv /var/log /data/

$ sudo ln -s /data/log /var/log

# 配置日志文件的访问目录权限,增加如下目录的权限
#  /data/log/mysql.err rw,
#  /data/log/mysql.log rw,
#  /data/log/mysql/ r,
#  /data/log/mysql/** rw,

$ sudo sed -i "s/^[ \t]*\/var\/log\/mysql\/\*\* rw,/  \/var\/log\/mysql\/** rw,\n\n  \/data\/log\/mysql.err rw,\n  \/data\/log\/mysql.log rw,\n  \/data\/log\/mysql\/ r,\n  \/data\/log\/mysql\/** rw,/g" /etc/apparmor.d/usr.sbin.mysqld

# 逐个启动服务，不如直接重启系统
$ sudo reboot

$ sudo service tomcat7 stop

$ sudo service denyhosts stop

$ sudo service php7.0-fpm stop

$ sudo service apache2 stop

$ sudo service mysql stop

$ sudo service nginx stop

$ sudo service apparmor stop

$ sudo mv /var/log /data/

$ sudo ln -s /data/log /var/log

# 配置日志文件的访问目录权限,增加如下目录的权限

# /data/log/mysql.err rw,

# /data/log/mysql.log rw,

# /data/log/mysql/ r,

# /data/log/mysql/** rw,

$ sudo sed -i "s/^[ \t]*\/var\/log\/mysql\/\*\* rw,/ \/var\/log\/mysql\/** rw,\n\n \/data\/log\/mysql.err rw,\n \/data\/log\/mysql.log rw,\n \/data\/log\/mysql\/ r,\n \/data\/log\/mysql\/** rw,/g" /etc/apparmor.d/usr.sbin.mysqld

# 逐个启动服务，不如直接重启系统

$ sudo reboot

如果依旧启动失败，并且 MySQL 是从低版本升级上来的，并且目前正在使用的版本大于或者等于 MySQL 5.7 ，执行 journalctl -xe 观察到类似如下内容：

-- Unit mysql.service has begun starting up.
Aug 20 10:16:50 AY130422143404983ad9 audit[8762]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysqld" requested_mask="r" denied_mask=
Aug 20 10:16:50 AY130422143404983ad9 kernel: audit_printk_skb: 21 callbacks suppressed
Aug 20 10:16:50 AY130422143404983ad9 kernel: audit: type=1400 audit(1566267410.233:325): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysq
Aug 20 10:16:50 AY130422143404983ad9 audit[8762]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=8762 comm="mysqld" requested_mask="r" deni
Aug 20 10:16:50 AY130422143404983ad9 audit[8762]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysqld" requested_mask="r" denied_mask=
Aug 20 10:16:50 AY130422143404983ad9 kernel: audit: type=1400 audit(1566267410.237:326): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=8762 co
Aug 20 10:16:50 AY130422143404983ad9 kernel: audit: type=1400 audit(1566267410.237:327): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysq
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.244672Z 0 [Warning] Changed limits: max_open_files: 1024 (requested 5000)
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.244721Z 0 [Warning] Changed limits: table_open_cache: 431 (requested 2000)
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.418600Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.418629Z 0 [Warning] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict 
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.420618Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.27-0ubuntu0.16.04.1-log) starting as process 8762 ...
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.422604Z 0 [ERROR] Could not open file '/var/log/mysql/error.log' for error logging: Permission denied
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.423358Z 0 [ERROR] Aborting
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.423499Z 0 [Note] Binlog end
Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.423685Z 0 [Note] /usr/sbin/mysqld: Shutdown complete
Aug 20 10:16:50 AY130422143404983ad9 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE

-- Unit mysql.service has begun starting up.

Aug 20 10:16:50 AY130422143404983ad9 audit[8762]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysqld" requested_mask="r" denied_mask=

Aug 20 10:16:50 AY130422143404983ad9 kernel: audit_printk_skb: 21 callbacks suppressed

Aug 20 10:16:50 AY130422143404983ad9 kernel: audit: type=1400 audit(1566267410.233:325): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysq

Aug 20 10:16:50 AY130422143404983ad9 audit[8762]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=8762 comm="mysqld" requested_mask="r" deni

Aug 20 10:16:50 AY130422143404983ad9 audit[8762]: AVC apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysqld" requested_mask="r" denied_mask=

Aug 20 10:16:50 AY130422143404983ad9 kernel: audit: type=1400 audit(1566267410.237:326): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/sys/devices/system/node/" pid=8762 co

Aug 20 10:16:50 AY130422143404983ad9 kernel: audit: type=1400 audit(1566267410.237:327): apparmor="DENIED" operation="open" profile="/usr/sbin/mysqld" name="/proc/8762/status" pid=8762 comm="mysq

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.244672Z 0 [Warning] Changed limits: max_open_files: 1024 (requested 5000)

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.244721Z 0 [Warning] Changed limits: table_open_cache: 431 (requested 2000)

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.418600Z 0 [Warning] TIMESTAMP with implicit DEFAULT value is deprecated. Please use --explicit_defaults_for_timestamp server

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.418629Z 0 [Warning] 'NO_ZERO_DATE', 'NO_ZERO_IN_DATE' and 'ERROR_FOR_DIVISION_BY_ZERO' sql modes should be used with strict

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.420618Z 0 [Note] /usr/sbin/mysqld (mysqld 5.7.27-0ubuntu0.16.04.1-log) starting as process 8762 ...

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.422604Z 0 [ERROR] Could not open file '/var/log/mysql/error.log' for error logging: Permission denied

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.423358Z 0 [ERROR] Aborting

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.423499Z 0 [Note] Binlog end

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.423685Z 0 [Note] /usr/sbin/mysqld: Shutdown complete

Aug 20 10:16:50 AY130422143404983ad9 systemd[1]: mysql.service: Main process exited, code=exited, status=1/FAILURE

那么，此时的MySQL的 apparmor 配置文件可能还没有更新，这个时候，我们需要手工在/etc/apparmor.d/usr.sbin.mysqld 增加几个文件目录的权限，如下：

/proc/*/status r,
/sys/devices/system/node/ r,
/sys/devices/system/node/node0/meminfo r,

/proc/*/status r,

/sys/devices/system/node/ r,

/sys/devices/system/node/node0/meminfo r,

另外，注意到我这边出现

Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.422604Z 0 [ERROR] Could not open file '/var/log/mysql/error.log' for error logging: Permission denied

1	Aug 20 10:16:50 AY130422143404983ad9 mysqld[8762]: 2019-08-20T02:16:50.422604Z 0 [ERROR] Could not open file '/var/log/mysql/error.log' for error logging: Permission denied

此时,如果检查目录权限，出现如下现象：

$ ls -la  /var/log/mysql/
total 256260
dr--r-s---   2 mysql adm        4096 Aug 20 10:04 .
drwxrwxr-x+ 21 root  syslog     4096 Aug 20 06:25 ..
-rw-r--r--   1 mysql adm           0 Aug 20 10:04 error.log
-r--r-x---+  1 mysql adm        2982 Aug 20 06:25 error.log.1
-r--r-x---+  1 mysql adm        3195 Aug 19 01:52 error.log.2.gz
-r--r-x---+  1 mysql adm          20 Aug 17 06:25 error.log.3.gz
-r--r-x---+  1 mysql adm          20 Aug 16 06:25 error.log.4.gz
-r--r-x---+  1 mysql adm          20 Aug 15 06:25 error.log.5.gz
-r--r-x---+  1 mysql adm          20 Aug 14 06:25 error.log.6.gz
-r--r-x---+  1 mysql adm          20 Aug 13 06:25 error.log.7.gz
-r--r-x---+  1 mysql adm          20 Aug 12 06:25 error.log.8.gz
-r--r-x---+  1 mysql adm    11235835 Aug 10 06:25 mysql-bin.000637
-r--r-x---+  1 mysql adm     9529581 Aug 11 06:25 mysql-bin.000638
-r--r-x---+  1 mysql adm     8299217 Aug 12 06:25 mysql-bin.000639
-r--r-x---+  1 mysql adm    15319155 Aug 13 06:25 mysql-bin.000640
-r--r-x---+  1 mysql adm    15816427 Aug 14 06:25 mysql-bin.000641
-r--r-x---+  1 mysql adm    47746113 Aug 15 06:25 mysql-bin.000642
-r--r-x---+  1 mysql adm    29508705 Aug 16 06:25 mysql-bin.000643
-r--r-x---+  1 mysql adm    29720349 Aug 17 06:25 mysql-bin.000644
-r--r-x---+  1 mysql adm    34429847 Aug 18 06:25 mysql-bin.000645
-r--r-x---+  1 mysql adm    10252663 Aug 18 19:10 mysql-bin.000646
-r--r-x---+  1 mysql adm     3971401 Aug 19 01:51 mysql-bin.000647
-r--r-x---+  1 mysql adm     1799987 Aug 19 06:25 mysql-bin.000648
-r--r-x---+  1 mysql adm    44653600 Aug 20 06:25 mysql-bin.000649
-r--r-x---+  1 mysql adm         416 Aug 19 06:25 mysql-bin.index

$ ls -la /var/log/mysql/

total 256260

dr--r-s--- 2 mysql adm 4096 Aug 20 10:04 .

drwxrwxr-x+ 21 root syslog 4096 Aug 20 06:25 ..

-rw-r--r-- 1 mysql adm 0 Aug 20 10:04 error.log

-r--r-x---+ 1 mysql adm 2982 Aug 20 06:25 error.log.1

-r--r-x---+ 1 mysql adm 3195 Aug 19 01:52 error.log.2.gz

-r--r-x---+ 1 mysql adm 20 Aug 17 06:25 error.log.3.gz

-r--r-x---+ 1 mysql adm 20 Aug 16 06:25 error.log.4.gz

-r--r-x---+ 1 mysql adm 20 Aug 15 06:25 error.log.5.gz

-r--r-x---+ 1 mysql adm 20 Aug 14 06:25 error.log.6.gz

-r--r-x---+ 1 mysql adm 20 Aug 13 06:25 error.log.7.gz

-r--r-x---+ 1 mysql adm 20 Aug 12 06:25 error.log.8.gz

-r--r-x---+ 1 mysql adm 11235835 Aug 10 06:25 mysql-bin.000637

-r--r-x---+ 1 mysql adm 9529581 Aug 11 06:25 mysql-bin.000638

-r--r-x---+ 1 mysql adm 8299217 Aug 12 06:25 mysql-bin.000639

-r--r-x---+ 1 mysql adm 15319155 Aug 13 06:25 mysql-bin.000640

-r--r-x---+ 1 mysql adm 15816427 Aug 14 06:25 mysql-bin.000641

-r--r-x---+ 1 mysql adm 47746113 Aug 15 06:25 mysql-bin.000642

-r--r-x---+ 1 mysql adm 29508705 Aug 16 06:25 mysql-bin.000643

-r--r-x---+ 1 mysql adm 29720349 Aug 17 06:25 mysql-bin.000644

-r--r-x---+ 1 mysql adm 34429847 Aug 18 06:25 mysql-bin.000645

-r--r-x---+ 1 mysql adm 10252663 Aug 18 19:10 mysql-bin.000646

-r--r-x---+ 1 mysql adm 3971401 Aug 19 01:51 mysql-bin.000647

-r--r-x---+ 1 mysql adm 1799987 Aug 19 06:25 mysql-bin.000648

-r--r-x---+ 1 mysql adm 44653600 Aug 20 06:25 mysql-bin.000649

-r--r-x---+ 1 mysql adm 416 Aug 19 06:25 mysql-bin.index

那么需要变更用户的所有者，早期版本支持所有者为 adm 用户组，新版本需要 mysql ,我们执行如下命令：

$ sudo chown -R mysql:mysql /var/log/mysql*

$ sudo service mysql restart

$ sudo chown -R mysql:mysql /var/log/mysql*

$ sudo service mysql restart

参考链接

在VirtualBox 5.2.22上安装Mac OS X Leopard(10.5)

在VirtualBox 5.2.22上安装Mac OS X Leopard(10.5)，具体步骤，依照下列的步骤操作即可。
继续阅读

解决ubuntu 16.04下adb shell报错"error: insufficient permissions for device"

最近在ubuntu 16.04下执行adb shell，时候报告如下错误：

$ adb shell
* daemon not running. starting it now on port 5037 *
* daemon started successfully *
error: insufficient permissions for device

$ adb shell

* daemon not running. starting it now on port 5037 *

* daemon started successfully *

error: insufficient permissions for device

原因为当前用户的权限不能调用系统底层的一些权限，需要提权，使用sudo执行即可解决此问题。

$ sudo adb kill-server

$ sudo adb shell

$ sudo adb kill-server

$ sudo adb shell

Apple的官方开源项目网站

Apple的开源其实做得很棒！http://www.opensource.apple.com/，这个Apple的官方开源网站真的是一个大宝藏。真的是不怕你知道，就怕你学不完。

WebKit就不用说了。在OS X和iOS分类下，有对应的WebKit的版本号，这里也可以快速知道相应操作系统里使用的WebKit版本。
Objective-C Runtime。objc运行时是如何工作的？如何使用mach-o里的__TEXT.__objc_xxx和__DATA._objc_xxx（__OBJC segment现在没有了？）？可以查看OS X分类下某个系统版本下的objc4-XXX目录。
Libc。想知道c库里的某个函数如何实现？可以查看OS X分类下某个系统版本下的Libc-XXX目录。
xnu。想学习内核？可以查看OS X分类下某个系统版本下的xnu-XXX目录。
想了解和学习各种工具如何实现？otool？nm？可以查看Developer Tools分类下某个Xcode版本下的cctools-XXX目录。nm.c就在这个目录里的msic目录里。
还有很多很多。。。
某个主题目录可以直接下载，而且，有一些主题里会有Xcode project文件，这样可以很方便查看和搜索。另外，某些主题的源代码应该是不完全的，不同的操作系统版本里会有不同，如果某个主题里的某个源代码在新的操作系统里没有找到，可以尝试在旧的操作系统里找一下。

http://www.opensource.apple.com/，你值得拥有！

参考链接

Apple Open Source

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