To reproduce the build failure do the following steps. Note that the first step is straight from the Ionic docs. Then, if you run the exact same sequence of steps but replace myFirstIonicApp with MyFirstIonicApp, you own’t reproduce the build failure. I suspect this is a cordova defect, but best that you steer Ionic users away from it.
ionic start myFirstIonicApp
ionic platform add ios
ionic plugin add https://github.com/wymsee/cordova-imagePicker.git
ionic build ios
ionic plugin add https://github.com/EddyVerbruggen/SocialSharing-PhoneGap-Plugin.git
ionic build iOS