Whenever Edebug is entered, it needs to save and restore certain data before even deciding whether to make trace information or stop the program.
max-lisp-eval-depth (see Eval) is increased to reduce Edebug’s
impact on the stack. You could, however, still run out of stack space when
using Edebug. You can also enlarge the value of
edebug-max-depth if Edebug reaches the limit of recursion depth
instrumenting code that contains very large quoted lists.
executing-kbd-macro is bound to nil
unless edebug-continue-kbd-macro is non-nil.