Copied from OpenBSD.

Fixes: ../src/getself.c:40:1: fatal error: opening dependency file
../obj/Release/TEngine/getself.d: No such file or directory

$OpenBSD: patch-src_getself_c,v 1.3 2017/11/11 11:24:42 kirby Exp $

--- a/src/getself.c
+++ b/src/getself.c
@@ -47,13 +47,7 @@ int get_number_cpus()
 const char *get_self_executable(int argc, char **argv)
 {
 	static char res[PATH_MAX];
-	int mib[4];
-	mib[0] = CTL_KERN;
-	mib[1] = KERN_PROC;
-	mib[2] = KERN_PROC_PATHNAME;
-	mib[3] = -1;
-	size_t cb = sizeof(res);
-	sysctl(mib,4,res,&cb,NULL,0);
+	realpath("${GAMEDIR}/", res);
 	return res;
 }