Cordova build failed with error code : EACCESS
$ cordova build android
Running command: /home/user/proj1/platforms/android/cordova/build 
execvp(): Permission denied
Error: /home/user/proj1/platforms/android/cordova/build: Command failed with exit code EACCES
    at ChildProcess.whenDone (/usr/lib/node_modules/cordova/node_modules/cordova-lib/src/cordova/superspawn.js:131:23)
    at ChildProcess.EventEmitter.emit (events.js:95:17)
    at Process.ChildProcess._handle.onexit (child_process.js:795:12)
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     OS  : Ubuntu 14.04
     npm version: 1.4.16
     cordova version : 3.5.0-0.2.4
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have added android platform to proj1
tried to re-installing cordova but did not work