https://osdn.net/projects/yash/ticket/47773

--- configure.orig	2023-04-07 19:40:18 UTC
+++ configure
@@ -746,6 +746,7 @@ END
 	checking "for ${i%:*}"
 	cat >"${tempsrc}" <<END
 ${confighdefs}
+#include <stdio.h>
 #if HAVE_CURSES_H
 #include <curses.h>
 #elif HAVE_NCURSES_H
@@ -756,8 +757,6 @@ ${confighdefs}
 #include <ncursesw/ncurses.h>
 #endif
 #include <${i%:*}>
-int putchar(int);
-
 int main(void) {
 /* Undeclared identifiers are a syntax error in C99, but many compilers assume
  * implicit declarations when they appear in a function call. We force compilers
