Source: See below, slightly modified for 17.2.0
Upstream: under review, https://patchwork.freedesktop.org/patch/157889/
Reason: Fix cross compiling

diff --git a/configure.ac b/configure.ac
index 0bd9650..c5dc8da 100644
--- a/configure.ac
+++ b/configure.ac
@@ -1696,12 +1696,18 @@ if test "x$with_platforms" = xauto; then
     with_platforms=$with_egl_platforms
 fi
 
-PKG_CHECK_MODULES([WAYLAND_SCANNER], [wayland-scanner],
+AC_ARG_WITH([wayland-scanner-path],
+    [AS_HELP_STRING([--with-wayland-scanner-path=PATH],
+        [Path to wayland-scanner (by default the path from
+        'pkg-config --variable=wayland_scanner wayland-scanner' is used)])],
+    [WAYLAND_SCANNER="$withval"],
+    [WAYLAND_SCANNER="auto"])
+if test x$WAYLAND_SCANNER = xauto; then
+    PKG_CHECK_MODULES([WAYLAND_SCANNER], [wayland-scanner],
         WAYLAND_SCANNER=`$PKG_CONFIG --variable=wayland_scanner wayland-scanner`,
-        WAYLAND_SCANNER='')
-if test "x$WAYLAND_SCANNER" = x; then
-    AC_PATH_PROG([WAYLAND_SCANNER], [wayland-scanner], [:])
+        WAYLAND_SCANNER=":")
 fi
+AC_SUBST(WAYLAND_SCANNER)
 
 PKG_CHECK_EXISTS([wayland-protocols >= $WAYLAND_PROTOCOLS_REQUIRED], [have_wayland_protocols=yes], [have_wayland_protocols=no])
 if test "x$have_wayland_protocols" = xyes; then
@@ -1718,7 +1724,7 @@ for plat in $platforms; do
         PKG_CHECK_MODULES([WAYLAND], [wayland-client >= $WAYLAND_REQUIRED wayland-server >= $WAYLAND_REQUIRED])
 
         if test "x$WAYLAND_SCANNER" = "x:"; then
-                AC_MSG_ERROR([wayland-scanner is needed to compile the wayland platform])
+                AC_MSG_ERROR([wayland-scanner is needed by Wayland platform but it could not be found and --with-wayland-scanner-path was not used])
         fi
         if test "x$have_wayland_protocols" = xno; then
                 AC_MSG_ERROR([wayland-protocols >= $WAYLAND_PROTOCOLS_REQUIRED is needed to compile the wayland platform])