I guess this should not happen for a major release.
UiAutomator is kind of broken. I've found this problem on a Nexus 4 and also on emulator, so it seems generic. Now when Chimpchat opens a connection (i.e. monkeyrunner) and you try to run uiautomator from a different adb shell you'll get
07-30 23:49:51.821: D/AndroidRuntime(2951): >>>>>> AndroidRuntime START com.android.internal.os.RuntimeInit <<<<<<
07-30 23:49:51.821: D/AndroidRuntime(2951): CheckJNI is OFF
07-30 23:49:51.831: D/dalvikvm(2951): Trying to load lib libjavacore.so 0x0
07-30 23:49:51.841: D/dalvikvm(2951): Added shared lib libjavacore.so 0x0
07-30 23:49:51.841: D/dalvikvm(2951): Trying to load lib libnativehelper.so 0x0
07-30 23:49:51.841: D/dalvikvm(2951): Added shared lib libnativehelper.so 0x0
07-30 23:49:51.981: D/AndroidRuntime(2951): Calling main entry com.android.commands.uiautomator.Launcher
07-30 23:49:51.991: D/AndroidRuntime(2951): Shutting down VM
07-30 23:49:51.991: W/dalvikvm(2951): threadid=1: thread exiting with uncaught exception (group=0x415b9700)
07-30 23:49:51.991: D/dalvikvm(2951): Note: class Landroid/app/ActivityManagerNative; has 163 unimplemented (abstract) methods
07-30 23:49:51.991: E/JavaBinder(2951): Unknown binder error code. 0xfffffff7
07-30 23:49:51.991: E/ServiceManager(2951): error in getService
07-30 23:49:51.991: E/ServiceManager(2951): android.os.RemoteException: Unknown binder error code. 0xfffffff7
07-30 23:49:51.991: E/ServiceManager(2951): at android.os.BinderProxy.transact(Native Method)
07-30 23:49:51.991: E/ServiceManager(2951): at android.os.ServiceManagerProxy.getService(ServiceManagerNative.java:123)
07-30 23:49:51.991: E/ServiceManager(2951): at android.os.ServiceManager.getService(ServiceManager.java:55)
07-30 23:49:51.991: E/ServiceManager(2951): at android.app.ActivityManagerNative$1.create(ActivityManagerNative.java:1893)
07-30 23:49:51.991: E/ServiceManager(2951): at android.app.ActivityManagerNative$1.create(ActivityManagerNative.java:1891)
07-30 23:49:51.991: E/ServiceManager(2951): at android.util.Singleton.get(Singleton.java:34)
07-30 23:49:51.991: E/ServiceManager(2951): at android.app.ActivityManagerNative.getDefault(ActivityManagerNative.java:73)
07-30 23:49:51.991: E/ServiceManager(2951): at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:76)
07-30 23:49:51.991: E/ServiceManager(2951): at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
07-30 23:49:51.991: E/ServiceManager(2951): at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)
07-30 23:49:51.991: E/ServiceManager(2951): at dalvik.system.NativeStart.main(Native Method)
07-30 23:49:51.991: I/Process(2951): Sending signal. PID: 2951 SIG: 9
07-30 23:49:51.991: E/AndroidRuntime(2951): *** FATAL EXCEPTION IN SYSTEM PROCESS: main
07-30 23:49:51.991: E/AndroidRuntime(2951): java.lang.IllegalStateException: UiAutomationService android.accessibilityservice.IAccessibilityServiceClient$Stub$Proxy@427adc60already registered!
07-30 23:49:51.991: E/AndroidRuntime(2951): at android.os.Parcel.readException(Parcel.java:1439)
07-30 23:49:51.991: E/AndroidRuntime(2951): at android.os.Parcel.readException(Parcel.java:1385)
07-30 23:49:51.991: E/AndroidRuntime(2951): at android.view.accessibility.IAccessibilityManager$Stub$Proxy.registerUiTestAutomationService(IAccessibilityManager.java:342)
07-30 23:49:51.991: E/AndroidRuntime(2951): at android.app.UiAutomationConnection.registerUiTestAutomationServiceLocked(UiAutomationConnection.java:173)
07-30 23:49:51.991: E/AndroidRuntime(2951): at android.app.UiAutomationConnection.connect(UiAutomationConnection.java:72)
07-30 23:49:51.991: E/AndroidRuntime(2951): at android.app.UiAutomation.connect(UiAutomation.java:188)
07-30 23:49:51.991: E/AndroidRuntime(2951): at com.android.uiautomator.core.UiAutomationShellWrapper.connect(UiAutomationShellWrapper.java:32)
07-30 23:49:51.991: E/AndroidRuntime(2951): at com.android.commands.uiautomator.DumpCommand.run(DumpCommand.java:74)
07-30 23:49:51.991: E/AndroidRuntime(2951): at com.android.commands.uiautomator.Launcher.main(Launcher.java:83)
07-30 23:49:51.991: E/AndroidRuntime(2951): at com.android.internal.os.RuntimeInit.nativeFinishInit(Native Method)
07-30 23:49:51.991: E/AndroidRuntime(2951): at com.android.internal.os.RuntimeInit.main(RuntimeInit.java:235)
07-30 23:49:51.991: E/AndroidRuntime(2951): at dalvik.system.NativeStart.main(Native Method)
07-30 23:49:51.991: E/AndroidRuntime(2951): Error reporting crash
07-30 23:49:51.991: E/AndroidRuntime(2951): java.lang.NullPointerException
07-30 23:49:51.991: E/AndroidRuntime(2951): at com.android.internal.os.RuntimeInit$UncaughtHandler.uncaughtException(RuntimeInit.java:76)
07-30 23:49:51.991: E/AndroidRuntime(2951): at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:693)
07-30 23:49:51.991: E/AndroidRuntime(2951): at java.lang.ThreadGroup.uncaughtException(ThreadGroup.java:690)
07-30 23:49:51.991: E/AndroidRuntime(2951): at dalvik.system.NativeStart.main(Native Method)
This was perfectly valid and correct on Android 4.2.x. It still requires some investigation, but I wanted to post it here just in case you find the same, at least you won't feel alone.
UPDATE: 2013-AUG-27:
AndroidViewClient/culebra version 4.0.0: now 100% pure python describes a solution for this problem
