Ensure that emacs uses GNU find. See components/emacs/README.

--- emacs-27.1/lisp/loaddefs.el.orig	2020-08-04 21:50:06.000000000 +0000
+++ emacs-27.1/lisp/loaddefs.el	2020-08-15 11:07:57.225527052 +0000
@@ -15065,7 +15065,7 @@
 The default grep program for `grep-command' and `grep-find-command'.
 This variable's value takes effect when `grep-compute-defaults' is called.")
 
-(defvar find-program (purecopy "find") "\
+(defvar find-program (purecopy "/usr/gnu/bin/find") "\
 The default find program.
 This is used by commands like `grep-find-command', `find-dired'
 and others.")
--- emacs-27.1/lisp/ldefs-boot.el.orig	2020-08-04 21:59:53.000000000 +0000
+++ emacs-27.1/lisp/ldefs-boot.el	2020-08-15 11:08:30.652017347 +0000
@@ -15065,7 +15065,7 @@
 The default grep program for `grep-command' and `grep-find-command'.
 This variable's value takes effect when `grep-compute-defaults' is called.")
 
-(defvar find-program (purecopy "find") "\
+(defvar find-program (purecopy "/usr/gnu/bin/find") "\
 The default find program.
 This is used by commands like `grep-find-command', `find-dired'
 and others.")
--- emacs-27.1/lisp/progmodes/grep.el.orig	2020-07-29 23:40:41.000000000 +0000
+++ emacs-27.1/lisp/progmodes/grep.el	2020-08-15 11:09:19.101533184 +0000
@@ -501,7 +501,7 @@
 This variable's value takes effect when `grep-compute-defaults' is called.")
 
 ;;;###autoload
-(defvar find-program (purecopy "find")
+(defvar find-program (purecopy "/usr/gnu/bin/find")
   "The default find program.
 This is used by commands like `grep-find-command', `find-dired'
 and others.")