discipline M-x grep + git-grep

.emacs snippet

;; grep-mode is stupid and does its parsing too early
(pushnew (lambda (buffer string)
           (when (eq major-mode 'grep-mode)
             (grep-mode)))
         compilation-finish-functions)

(defun git-grep ()
  (interactive)
  (require 'grep)
  (let ((grep-command "git --no-pager grep -nH -e ")
        (grep-use-null-device nil))
    (grep-apply-setting 'grep-command grep-command)
    (grep-apply-setting 'grep-use-null-device grep-use-null-device )
    (call-interactively #'grep))
  (grep-apply-setting 'grep-command grep-command)
  (grep-apply-setting 'grep-use-null-device grep-use-null-device))