If we're calling (receive-message), and no message available, we can't interrupt with ^C slave should be in SLAVE-LISTENER package. or at least, not exported from MPIpackage Note also (getcwd): (getcwd) => reports too many allocated blocks ?? NOTE that the following workaround does work, however: (getcwd (make-array 256 :element-type 'string-char :fill-pointer t :static t))