Only in bash-4.3.30: build
diff -ur bash-4.3.30.dist/builtins/echo.def bash-4.3.30/builtins/echo.def
--- bash-4.3.30.dist/builtins/echo.def	2011-06-29 09:55:58.000000000 -0400
+++ bash-4.3.30/builtins/echo.def	2016-06-03 17:40:57.834915855 -0400
@@ -108,8 +108,9 @@
 echo_builtin (list)
      WORD_LIST *list;
 {
-  int display_return, do_v9, i, len;
-  char *temp, *s;
+  int display_return, do_v9, i, j, len, malloc_len;
+  char *temp, *s, *m;
+  WORD_LIST *save_list;
 
   do_v9 = xpg_echo;
   display_return = 1;
@@ -162,6 +163,30 @@
   clearerr (stdout);	/* clear error before writing and testing success */
 
   terminate_immediately++;
+  malloc_len = 0;
+  m = NULL;
+  save_list = list;
+  while (list)
+    {
+      i = len = 0;
+      temp = do_v9 ? ansicstr (list->word->word, STRLEN (list->word->word), 1, &i, &len)
+		   : list->word->word;
+      if (!temp)
+        continue;
+      malloc_len += do_v9 ? len : strlen(temp);
+      if (do_v9)
+	free (temp);
+      list = list->next;
+      if (list)
+        malloc_len++;
+    }
+  if (display_return)
+    malloc_len++;
+  m = malloc(malloc_len);
+  if (m == NULL)
+    fatal_error ("echo: could not allocate %lu bytes", (unsigned long)malloc_len);
+  list = save_list;
+  j = 0;
   while (list)
     {
       i = len = 0;
@@ -169,19 +194,13 @@
 		   : list->word->word;
       if (temp)
 	{
-	  if (do_v9)
-	    {
-	      for (s = temp; len > 0; len--)
-		putchar (*s++);
-	    }
-	  else	    
-	    printf ("%s", temp);
-#if defined (SunOS5)
-	  fflush (stdout);	/* Fix for bug in SunOS 5.5 printf(3) */
-#endif
+	  if (!do_v9)
+              len = strlen(temp);
+          memmove(m + j, temp, len);
+          j += len;
+          if (do_v9)
+            free (temp);
 	}
-      if (do_v9 && temp)
-	free (temp);
       list = list->next;
       if (i)
 	{
@@ -189,11 +208,15 @@
 	  break;
 	}
       if (list)
-	putchar(' ');
+	m[j++] = ' ';
     }
-
   if (display_return)
-    putchar ('\n');
+    m[j++] = '\n';
+  write(STDOUT_FILENO, m, j);
+  free(m);
+#if defined (SunOS5)
+  fflush (stdout);	/* Fix for bug in SunOS 5.5 printf(3) */
+#endif
 
   terminate_immediately--;
   return (sh_chkwrite (EXECUTION_SUCCESS));
diff -ur bash-4.3.30.dist/configure bash-4.3.30/configure
--- bash-4.3.30.dist/configure	2014-02-11 10:38:00.000000000 -0500
+++ bash-4.3.30/configure	2016-05-16 23:04:59.481616025 -0400
@@ -2853,6 +2853,7 @@
 sparc-linux*)	opt_bash_malloc=no ;;	# sparc running linux; requires ELF
 #*-freebsd*-gnu)	opt_bash_malloc=no ;;	# there's some undetermined problem here
 #*-freebsd*)	opt_bash_malloc=no ;;	# they claim it's better; I disagree
+*-akaros*)	opt_bash_malloc=no ;;	# they claim it needs eight-bit alignment
 *-openbsd*)	opt_bash_malloc=no ;;	# they claim it needs eight-bit alignment
 *-mirbsd*)	opt_bash_malloc=no ;;	# they claim it needs eight-bit alignment
 *-aix*)		opt_bash_malloc=no ;;	# AIX machines
diff -ur bash-4.3.30.dist/error.c bash-4.3.30/error.c
--- bash-4.3.30.dist/error.c	2014-01-17 08:09:33.000000000 -0500
+++ bash-4.3.30/error.c	2016-05-25 13:40:26.978379551 -0400
@@ -487,3 +487,32 @@
 {
   report_error (_("%s: readonly variable"), s);
 }
+
+#if defined (USE_AKAROS_STRERROR)
+#ifndef MAX_ERRSTR_LEN
+#define MAX_ERRSTR_LEN 128
+#endif
+char *
+akaros_strerror(e)
+      int e;
+{
+  static char emsg[2*MAX_ERRSTR_LEN];
+  char ebuf[MAX_ERRSTR_LEN];
+  size_t len;
+  int serrno;
+  char *estr, *strerror_str;
+
+  serrno = errno;
+  estr = errstr ();
+  strerror_str = strerror_r (e, ebuf, sizeof (ebuf));
+  len = strlen (strerror_str);
+  if (len > (sizeof (emsg) - 1))
+    len = sizeof (emsg) - 1;
+  memmove (emsg, strerror_str, len);
+  if (e == serrno && estr && *estr)
+    snprintf (emsg + len, sizeof (emsg) - len, ", %s", estr);
+  ebuf[sizeof (ebuf) - 1] = '\0';
+
+  return emsg;
+}
+#endif
diff -ur bash-4.3.30.dist/mksyntax.c bash-4.3.30/mksyntax.c
--- bash-4.3.30.dist/mksyntax.c	2012-07-29 19:48:38.000000000 -0400
+++ bash-4.3.30/mksyntax.c	2016-05-25 11:59:57.560352289 -0400
@@ -40,6 +40,10 @@
 extern int errno;
 #endif
 
+#ifdef strerror
+#undef strerror
+#endif
+
 #ifndef HAVE_STRERROR
 extern char *strerror();
 #endif
diff -ur bash-4.3.30.dist/support/config.guess bash-4.3.30/support/config.guess
--- bash-4.3.30.dist/support/config.guess	2013-12-16 16:02:33.000000000 -0500
+++ bash-4.3.30/support/config.guess	2016-05-16 23:04:12.844336864 -0400
@@ -219,6 +219,10 @@
 	UNAME_MACHINE_ARCH=`arch | sed 's/Bitrig.//'`
 	echo ${UNAME_MACHINE_ARCH}-unknown-bitrig${UNAME_RELEASE}
 	exit ;;
+    *:Akaros:*:*)
+	UNAME_MACHINE_ARCH=x86_64
+	echo x86_64-ucb-akaros1.0
+	exit ;;
     *:OpenBSD:*:*)
 	UNAME_MACHINE_ARCH=`arch | sed 's/OpenBSD.//'`
 	echo ${UNAME_MACHINE_ARCH}-unknown-openbsd${UNAME_RELEASE}
diff -ur bash-4.3.30.dist/support/config.sub bash-4.3.30/support/config.sub
--- bash-4.3.30.dist/support/config.sub	2013-12-17 10:49:47.000000000 -0500
+++ bash-4.3.30/support/config.sub	2016-05-16 23:05:28.906423063 -0400
@@ -1356,7 +1356,7 @@
 	      | -hpux* | -unos* | -osf* | -luna* | -dgux* | -auroraux* | -solaris* \
 	      | -sym* | -kopensolaris* | -plan9* \
 	      | -amigaos* | -amigados* | -msdos* | -newsos* | -unicos* | -aof* \
-	      | -aos* | -aros* \
+	      | -akaros* | -aos* | -aros* \
 	      | -nindy* | -vxsim* | -vxworks* | -ebmon* | -hms* | -mvs* \
 	      | -clix* | -riscos* | -uniplus* | -iris* | -rtu* | -xenix* \
 	      | -hiux* | -386bsd* | -knetbsd* | -mirbsd* | -netbsd* \