* autogen.sh: Add --no-check option. (Bug#25359)

autogen.sh

@@ -103,6 +103,7 @@ check_version ()
     return 2
 }
 
+do_check=true
 do_autoconf=false
 test $# -eq 0 && do_autoconf=true
 do_git=false
@@ -111,6 +112,9 @@ for arg; do
     case $arg in
       --help)
 	exec echo "$0: usage: $0 [all|autoconf|git]";;
+      --no-check)
+        do_check=false
+        test $# -eq 1 && do_autoconf=true;;
       all)
 	do_autoconf=true
 	test -e .git && do_git=true;;
@@ -128,6 +132,8 @@ done
 
 if $do_autoconf; then
 
+  if $do_check; then
+
     echo 'Checking whether you have the necessary tools...
 (Read INSTALL.REPO for more details on building Emacs)'
 
@@ -208,11 +214,8 @@ make install.  Add the installation directory to your PATH and re-run
 this script.
 
 If you know that the required versions are in your PATH, but this
-script has made an error, then you can simply run
-
-autoreconf -fi -I m4
-
-instead of this script.
+script has made an error, then you can simply re-run this script with
+the --no-check option.
 
 Please report any problems with this script to bug-gnu-emacs@gnu.org .'
 
@@ -221,6 +224,8 @@ Please report any problems with this script to bug-gnu-emacs@gnu.org .'
 
     echo 'Your system has the required tools.'
 
+  fi                            # do_check
+
   ## Create nt/gnulib.mk if it doesn't exist, as autoreconf will need it.
   if test ! -f nt/gnulib.mk; then
       echo 'Inferring nt/gnulib.mk from lib/gnulib.mk ...'