I've upgraded to 2.1 and am using the cmd to build a native IOS app but the build fails with:

sencha package build -p ./packager.json 
Sencha Cmd v3.0.0.250
codesign_allocate: object: /webroot/[abc]/sencha_2.1/converted/build///[myapp].app/stbuild_template malformed object (unknown load command 34)
../build///[myapp].app: object file format invalid or unsuitable
The application was successfully packaged
Failed to execute system command while signing application with error 256
Failed to package application

[ERR]        stbuild exited with non-zero code : 6
If I set the platform to iOSSimulator the build works and runs the simulator ok.

I'm running on OSX.

Here's my package.json:

    "applicationId":"com.[my company].[myapp]",
         "provisionProfile": "/[my path]/provisioning_profiles/[myapp].mobileprovision",
        "bundleSeedId":"[my bundle seed]",
"icon": {
                "57": "resources/icons/Icon.png",
                "72": "resources/icons/Icon~ipad.png",
                "114": "resources/icons/Icon@2x.png",
                "144": "resources/icons/Icon~ipad@2x.png"
    "certificateAlias":"iPhone Distribution: [my company]",
    "orientations": [
Has anyone seen this or got any suggestions?