This section applies only on UNIX and UNIX-based systems, including Mac OS X.
By default, the Shell tool runs the UNIX command shell known as bash. If you would rather use a different shell (such as csh, tcsh, ksh, etc.), or if you do not have bash available on your UNIX system, then change the value of the variable editor:*shell-shell*, which has the value nil by default. This means that the Shell tool will use the value of the variable ESHELL or SHELL if set, or one of "/bin/sh" (system V) and "/bin/csh" (otherwise).
LispWorks IDE User Guide (Macintosh version) - 12 Feb 2015