TTY write error on IOS 15.2(4)M3

Question

I am using tracking and EEM for doing something like link-state tracking on an ISR G2.
But, I got an error only the first time run of the EEM script after rebooting the router.
From the second time EEM script works fine and set the interface shutdown properly.
Error Log:
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: TTY write error
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     while executing
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: "::cisco::eem::tty_write $fd $cmd"
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     (procedure "cli_write" line 8)
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     invoked from within
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: "cli_write $fd "$cmd""
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     (procedure "cli_exec" line 2)
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     invoked from within
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: "cli_exec $cli1(fd) "enable""
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     invoked from within
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: "$slave eval $Contents"
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     (procedure "eval_script" line 7)
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     invoked from within
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: "eval_script slave $scriptname"
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     invoked from within
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: "if {$security_level == 1} {       #untrusted script
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:      interp create -safe slave
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:      interp share {} stdin slave
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:      interp share {} stdout slave
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: ..."
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl:     (file "tmpsys:/lib/tcl/base.tcl" line 50)
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: Tcl policy execute failed:
*Aug 13 04:58:58.083: %HA_EM-6-LOG: track101.tcl: TTY write error
Configs:
track 101 interface GigabitEthernet0/0 line-protocol
event manager directory user policy flash:
event manager policy track101.tcl
Script:
::cisco::eem::event_register_track 101 state down
namespace import ::cisco::eem::*
namespace import ::cisco::lib::*
array set arr_einfo [event_reqinfo]
if [catch {cli_open} result] {
    error $result $errorInfo
} else {
    array set cli1 $result
if [catch {cli_exec $cli1(fd) "enable"} _cli_result] {
    error $_cli_result $errorInfo
if [catch {cli_exec $cli1(fd) "conf t"} _cli_result] {
    error $_cli_result $errorInfo
if [catch {cli_exec $cli1(fd) "interface BRI0"} _cli_result] {
    error $_cli_result $errorInfo
if [catch {cli_exec $cli1(fd) "shut"} _cli_result] {
    error $_cli_result $errorInfo
# Close open cli before exit.
catch {cli_close $cli1(fd) $cli1(tty_id)} result

Answer 1

This is bug CSCuh49281.  It has to do with exec-timeout being configured.  The workaround is to set the exec-timeout to default.  It is not limited to EEM, though.  Telnet sessions are also affected.