https://github.com/termux/termux-packages/issues/15852

--- a/telnet/sys_bsd.c
+++ b/telnet/sys_bsd.c
@@ -63,6 +63,10 @@
 #include <sys/select.h>
 #include <attribute.h>
 
+#ifdef __ANDROID__
+#include <termios.h>
+#endif
+
 #include "ring.h"
 
 #include "defines.h"