我在Linux上为Android构建MuPDF时遇到了困难。我完全遵循了如何为Android 构建MuPDF的指导
运行命令"ant debug"时生成失败，并出现以下错误-
/home/georgew/AndroidSDK/android-sdk-linux/tools/ant/build.xml:653:执行此行时发生以下错误：
/home/georgew/AndroidSDK/android-sdk-linux/tools/ant/build.xml:698：返回null：132
我花了一天的时间尝试谷歌能找到的每一个建议的解决方案。除了返回的null值可能不同之外，它们都会因此错误而失败。
构建系统是运行Scientific Linux 6.3的Pentium4。Ant是从源代码编译的，因为需要比SL6提供的版本更新的版本。
以下是运行"ant-d debug"的最后几行输出
Class com.android.ant.RenderScriptTask$1 loaded from ant loader (parentFirst)
[echo] ----------
[echo] Handling Resources...
Property "android.library" has not been set
[aapt] Generating resource IDs...
Class org.apache.tools.ant.types.Commandline$Argument loaded from parent loader (parentFirst)
[aapt] Current OS is Linux
[aapt] Executing '/home/georgew/AndroidSDK/android-sdk-linux/build-tools/21.0.2/aapt' with arguments:
[aapt] 'package'
[aapt] '-f'
[aapt] '-m'
[aapt] '-0'
[aapt] 'apk'
[aapt] '-M'
[aapt] '/home/georgew/AndroidSDK/src/mupdf/platform/android/bin/AndroidManifest.xml'
[aapt] '-S'
[aapt] '/home/georgew/AndroidSDK/src/mupdf/platform/android/bin/res'
[aapt] '-S'
[aapt] '/home/georgew/AndroidSDK/src/mupdf/platform/android/res'
[aapt] '-I'
[aapt] '/home/georgew/AndroidSDK/android-sdk-linux/platforms/android-16/android.jar'
[aapt] '-J'
[aapt] '/home/georgew/AndroidSDK/src/mupdf/platform/android/gen'
[aapt] '--generate-dependencies'
[aapt] '-G'
[aapt] '/home/georgew/AndroidSDK/src/mupdf/platform/android/bin/proguard.txt'
[aapt]
[aapt] The ' characters around the executable and arguments are
[aapt] not part of the command.
Execute:Java13CommandLauncher: Executing '/home/georgew/AndroidSDK/android-sdk-linux/build-tools/21.0.2/aapt' with arguments:
'package'
'-f'
'-m'
'-0'
'apk'
'-M'
'/home/georgew/AndroidSDK/src/mupdf/platform/android/bin/AndroidManifest.xml'
'-S'
'/home/georgew/AndroidSDK/src/mupdf/platform/android/bin/res'
'-S'
'/home/georgew/AndroidSDK/src/mupdf/platform/android/res'
'-I'
'/home/georgew/AndroidSDK/android-sdk-linux/platforms/android-16/android.jar'
'-J'
'/home/georgew/AndroidSDK/src/mupdf/platform/android/gen'
'--generate-dependencies'
'-G'
'/home/georgew/AndroidSDK/src/mupdf/platform/android/bin/proguard.txt'
The ' characters around the executable and arguments are
not part of the command.
BUILD FAILED
/home/georgew/AndroidSDK/android-sdk-linux/tools/ant/build.xml:653: The following error occurred while executing this line:
/home/georgew/AndroidSDK/android-sdk-linux/tools/ant/build.xml:698: null returned: 132
at org.apache.tools.ant.taskdefs.ExecTask.runExecute(ExecTask.java:650)
at org.apache.tools.ant.taskdefs.ExecTask.runExec(ExecTask.java:676)
at org.apache.tools.ant.taskdefs.ExecTask.execute(ExecTask.java:502)
at com.android.ant.AaptExecTask.execute(AaptExecTask.java:703)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68)
at com.android.ant.IfElseTask.execute(IfElseTask.java:120)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.taskdefs.Sequential.execute(Sequential.java:68)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.taskdefs.MacroInstance.execute(MacroInstance.java:398)
at org.apache.tools.ant.UnknownElement.execute(UnknownElement.java:291)
at sun.reflect.GeneratedMethodAccessor4.invoke(Unknown Source)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:616)
at org.apache.tools.ant.dispatch.DispatchUtils.execute(DispatchUtils.java:106)
at org.apache.tools.ant.Task.perform(Task.java:348)
at org.apache.tools.ant.Target.execute(Target.java:390)
at org.apache.tools.ant.Target.performTasks(Target.java:411)
at org.apache.tools.ant.Project.executeSortedTargets(Project.java:1397)
at org.apache.tools.ant.Project.executeTarget(Project.java:1366)
at org.apache.tools.ant.helper.DefaultExecutor.executeTargets(DefaultExecutor.java:41)
at org.apache.tools.ant.Project.executeTargets(Project.java:1249)
at org.apache.tools.ant.Main.runBuild(Main.java:801)
at org.apache.tools.ant.Main.startAnt(Main.java:218)
at org.apache.tools.ant.launch.Launcher.run(Launcher.java:280)
at org.apache.tools.ant.launch.Launcher.main(Launcher.java:109)
经过进一步研究，问题不在于构建MuPDF。问题是，较新版本的SDK中的aapt是在支持SSE2的情况下编译的，并且在较旧的计算机中已损坏。
可用的解决方案是在用于构建的计算机上下载并编译SDK，在更现代化的计算机上安装SDK并构建项目，或者查找在不支持SSE2的情况下编译的最新版本的aapt的副本。
我搜索并找到了一个jar文件，apktool-2.0.jar，从中提取了aapt，构建成功完成。