Sencha Touch用sencha app build native打包应用程序出现问题

今天在安装好SDK后在Ruby的Start Command Prompt命令行窗口输入sencha app build native用进行打包时，出现了以下问题：

BUILD FAILED
F:\Android\android-sdk\tools\ant\build.xml:888: The following error occurred whi
le executing this line:
F:\Android\android-sdk\tools\ant\build.xml:890: The following error occurred whi
le executing this line:
F:\Android\android-sdk\tools\ant\build.xml:902: The following error occurred whi
le executing this line:
F:\Android\android-sdk\tools\ant\build.xml:283: null returned: 1

Total time: 2 seconds
""F:\Android\android-sdk\tools\android" create project --target android-17 --nam
e MyFirstApp --activity STActivity --path "F:\sencha_app\fisrtApp/build/native-p
ackage-mobile/MyFirstApp/packager.json\/" --package com.sencha.MyFirstApp"
Could not run ant with error: 1
Failed to package application


[ERR]
[ERR] BUILD FAILED
[ERR] com.sencha.exceptions.ExProcess: stbuild exited with non-zero code : 7
[ERR]   at sun.reflect.DelegatingMet
[ERR] hodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
[ERR]
[ERR] Total time: 9 seconds
[ERR] The following error occurred while executing this line:
F:\sencha_app\fisrtApp\.sencha\app\build-impl.xml:422: The following error occur
red while executing this line:
F:\sencha_app\fisrtApp\.sencha\app\packager-impl.xml:112: The following error oc
curred while executing this line:
F:\sencha_app\fisrtApp\.sencha\app\packager-impl.xml:114: The following error oc
curred while executing this line:
F:\sencha_app\fisrtApp\.sencha\app\packager-impl.xml:98: The following error occ
urred while executing this line:
F:\sencha_app\fisrtApp\.sencha\app\packager-impl.xml:7: com.sencha.exceptions.Ex
Process: stbuild exited with non-zero code : 7

后来发现是SDK的Android SDK build-tools的版本问题，需要在Android SDK目录中打开SDK Manager，在Tools中把当前的Android SDK build-tools删除掉，重新安装一个旧的版本就可以解决了。