Make Emacs understand MSBuild Exec task compilation output

ak-msbuildify-compilation.el

(defun ak-msbuildify-regexp-str (s)
  (replace-regexp-in-string "\\^" "^ \\\\{0,2\\\\}" s))

(defun ak-msbuildify-alist-alist (xss-orig)
    (let* ((xss (copy-alist xss-orig))
	   (l xss))
      (while (consp l)
	;; l is (('symbol REGEXP ...) ...)
	(let* ((x (copy-sequence (car l))) ;; unshare with the original alist
	       (r (cdr x)))
	  (setcar r (ak-msbuildify-regexp-str (car r)))
	  (setcar l x))
	(setq l (cdr l)))
      xss))

(defun ak-msbuildify-compilation ()
  "Replace the normal regexps in ‘compilation-error-regexp-alist-alist’ to match output of MS Build Exec tasks.

The console logger in MS Build indents output from the commands
that are invoked by 2 columns.  This function modifies the
regexps that try to match compiler build output by replacing
their use of \"^\" by a regexp that matches beginning of line
followed by upto 2 spaces."
  (interactive)
  (when (not (boundp 'ak-compilation-error-regexp-alist-alist))
    (setq ak-compilation-error-regexp-alist-alist (copy-alist compilation-error-regexp-alist-alist))
    (setq compilation-error-regexp-alist-alist (ak-msbuildify-alist-alist compilation-error-regexp-alist-alist))))