(compilation-error-regexp-alist-alist) <gnu>:

Use shy regexp.  Fix incorrect backref to potentially unmatched group.

lisp/progmodes/compile.el

@@ -224,9 +224,9 @@ of[ \t]+\"?\\([a-zA-Z]?:?[^\":\n]+\\)\"?:" 3 2 nil (1))
 
     (gnu
      "^\\(?:[[:alpha:]][-[:alnum:].]+: ?\\)?\
-\\([/.]*[a-zA-Z]:?[^ \t\n:]*\\|{standard input}\\): ?\
-\\([0-9]+\\)\\([.:]?\\)\\([0-9]+\\)?\
-\\(?:-\\(?:\\([0-9]+\\)\\3\\)?\\.?\\([0-9]+\\)?\\)?:\
+\\(.+?\\): ?\
+\\([0-9]+\\)\\(?:\\([.:]\\)\\([0-9]+\\)\\)?\
+\\(?:-\\([0-9]+\\)?\\(?:\\3\\([0-9]+\\)\\)?\\)?:\
 \\(?: *\\(\\(?:Future\\|Runtime\\)?[Ww]arning\\|W:\\)\\|\
  *\\([Ii]nfo\\(?:\\>\\|rmationa?l?\\)\\|I:\\|instantiated from\\)\\)?"
      1 (2 . 5) (4 . 6) (7 . 8))