Problem adding cordova plugin after build

I'm not sure whether this is a cordova or sencha touch problem. I have a project I already worked on (for quite a while), now I want to add some other cordova plugin to that project.

Whenever I do

Code:

sencha app build -run native

I get the following error:

Code:

[ERR]  The following error occurred while executing this line:
/Users/martin/phonegapprojects/touch-2.3.1 copy/ibus/.sencha/app/build-impl.xml:422: The following error occurred while executing this line:
/Users/martin/phonegapprojects/touch-2.3.1 copy/ibus/.sencha/app/cordova-impl.xml:118: The following error occurred while executing this line:
jar:file:/Users/martin/bin/Sencha/Cmd/4.0.4.84/sencha.jar!/com/sencha/ant/antlib.xml:608: shellscript returned: 1

Any ideas about why this is happening?