$ ant release
Buildfile: E:\AS_VOD\build.xml
[taskdef] Could not load definitions from resource anttasks.properties. It could not be found.
[taskdef] Could not load definitions from resource emma_ant.properties. It could not be found.
-pre-special-task:
BUILD FAILED
E:\AS_VOD\build.xml:1270: Problem: failed to create task or type if
Cause: The name is undefined.
Action: Check the spelling.
Action: Check that any custom tasks/types have been declared.
Action: Check that any / declarations have taken place.
在用ant打包时候出现的错误，求大神帮忙分析一下