Controls whether compile-file handles compilation errors.
If an error occurs during compilation of a form by compile-file, an error handler normally causes the compilation of that form to be skipped, and the error is reported later.
When *compiler-break-on-error*
is non-nil, an error during compilation by compile-file is signaled and the debugger is entered.
LispWorks User Guide and Reference Manual - 13 Feb 2015