Problem with Flash Builder command line build using Apache Ant( task)

When I use <fb.exportReleaseBuild> task to build by command line, one error occurred.

(FlashBuild4.7 premium)

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fb.exportReleaseBuild] com.adobe.air.InvalidInputException: An implementation f

or native extension 'InputMethodContext' required by the application was not fou

nd for the target platform.

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Now my project used native extensions. (eg. libs/InputMethodExtension.ane)

So how am I write to build.xml for using native extensions.

Thanks!