1. xemacs
  2. vm


vm / README.bytecompile

Kyle sez:

    Rebuild VM with make, always, or there will be trouble.  The
    compiler has to know about every macro used in a Lisp source
    file so that they can be expanded.  If the bytecode interpreter
    encounters a macro at runtime, it will testily bark the exception

    Invalid function: (macro . #<compiled-function (pos &optional buffer) "...(9)" [set-marker (make-marker) pos buffer] 4>)

So, if you must edit and rebuild VM from the installed package, edit
Makefile-kj and use `make -f Makefile-kj ...'.