(setq path-separator ";")
;; Set the null device (for compile.el).
-;; #### There should be such a global thingy as null-device - kkm
-(setq grep-null-device "NUL")
+;; Backward-compatibility; recent compile.el uses null-device if available.
+(setq grep-null-device null-device)
;; Set the grep regexp to match entries with drive letters.
(setq grep-regexp-alist