search for: tcl_servicemodehook

...ND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug. The process has forked and you cannot use this CoreFoundation functionality safely. You MUST exec(). Break on __THE_PROCESS_HAS_FORKED_AND_YOU_CANNOT_USE_THIS_COREFOUNDATION_FUNCTIONALITY___YOU_MUST_EXEC__() to debug. Tcl_ServiceModeHook: Notifier not initialized [[1]] NULL [[2]] [1] 1.414 [[3]] [1] 1.732 The first element is obviously wrong, and the warning messages are scary. Restarting R eliminated all the problems. This seems to be something odd about the install and load process.