Upstream commit added this code:
https://github.com/wayland-project/wayland/commit/4a1f348c20157db7bd7c759fdeb23fbe8729c571

For some reasones something goes wrong and HAVE_STRNDUP does not get defined on rosa2016.1,
(no problems on rosa2019.05 and rosa2019.1).

The compiler fails:
../../third_party/wayland/src/src/scanner.c:979:1: error: expected identifier or '('
strndup(const char *s, size_t size)

glibc in rosa2016.1-rosa2019.1 does have strndup, workaround this issue by removing not needed code.

// mikhailnov, 09.01.2021

diff --git a/src/scanner.c b/src/scanner.c
index 7ed1ba1a..2b3adbda 100644
--- a/third_party/wayland/src/src/scanner.c
+++ b/third_party/wayland/src/src/scanner.c
@@ -974,17 +916,6 @@
 
 }
 
-#ifndef HAVE_STRNDUP
-char *
-strndup(const char *s, size_t size)
-{
-	char *r = malloc(size + 1);
-	strncpy(r, s, size);
-	r[size] = '\0';
-	return r;
-}
-#endif
-
 static void
 end_element(void *data, const XML_Char *name)
 {