A common cause of errors seen while building (delivering) an application is running part of the application's runtime initialization, or something else that assumes the application is already running.
One error sometimes seen is
"Not yet multiprocessing."
and other likely build phase errors include those arising from code that assumes something about the runtime environment.
Such initializations should be done at the start of the runtime phase, as described in Separate runtime initializations from the build phase.
LispWorks Release Notes and Installation Guide - 23 Dec 2011