Submitted for upstream in https://github.com/tsl0922/ttyd/pull/253

diff -u -r ../ttyd-1.4.2/src/utils.c ./src/utils.c
--- ../ttyd-1.4.2/src/utils.c	2018-09-12 04:18:04.000000000 +0000
+++ ./src/utils.c	2018-09-14 19:18:03.508092637 +0000
@@ -5,7 +5,7 @@
 #include <string.h>
 #include <signal.h>
 
-#ifdef __linux__
+#if defined(__linux__) && !defined(__ANDROID__)
 // https://github.com/karelzak/util-linux/blob/master/misc-utils/kill.c
 const char *sys_signame[NSIG] = {
     "zero",  "HUP",  "INT",   "QUIT", "ILL",   "TRAP", "ABRT", "UNUSED",