Automatic signing is broken with xcode 9. Because with those changes the development team isn't given to the xcode commandline in automatic signing mode.
The development team must be always given to the xcode commandline regardless if automatic signing is used or not!
In Manual signing mode only an provisioning profile must be provided additional to the teamid.
The selection of the development team should be restored to the old behaviour.
E.g. the code in XCodeBuilder.java should be changed from
to something like this (untestet)
The "-allowProvisioningUpdates" option exists only in xcode >= 9 This will break usage of the plugin with xcode < 9