>From 8ece63cd67d158b0349dda83c303e1f02a947f40 Mon Sep 17 00:00:00 2001
From: Alan Third <alan@idiocy.org>
Date: Sat, 22 Jun 2019 21:13:50 +0100
Subject: [PATCH] Provide a useful message if macuvs.h doesn't exist
 (bug#36332)

* configure.ac (with-ns): Error out if attempting to configure with
Cocoa but macuvs.h doesn't exist.
---
 configure.ac | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/configure.ac b/configure.ac
index 0507f58054..d7efe467fa 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1963,7 +1963,12 @@ AC_DEFUN
   # macfont.o requires macuvs.h which is absent after 'make extraclean',
   # so avoid NS_IMPL_COCOA if macuvs.h is absent.
   # Even a headless Emacs can build macuvs.h, so this should let you bootstrap.
-  if test "${opsys}" = darwin && test -f "$srcdir/src/macuvs.h"; then
+  if test "${opsys}" = darwin; then
+     if test \! -f "$srcdir/src/macuvs.h"; then
+       AC_MSG_ERROR([Cocoa build requested, however macuvs.h is missing.
+Rerun configure with the option '--without-ns' and run make before
+configuring '--with-ns'.])
+     fi
      NS_IMPL_COCOA=yes
      ns_appdir=`pwd`/nextstep/Emacs.app
      ns_appbindir=${ns_appdir}/Contents/MacOS
-- 
2.21.0