repeated expression at repl is sometimes disqualified

gistfile1.txt

(gdb) show env
MANPATH=
SHELL=/bin/bash
TERM=dumb
TMPDIR=/var/folders/k3/378c5t615d747q30wd1ps4pw0000gn/T/
Apple_PubSub_Socket_Render=/tmp/launch-n8TMSQ/Render
EMACSDATA=/Applications/Emacs.app/Contents/Resources/etc
EMACSPATH=/Applications/Emacs.app/Contents/MacOS/bin
USER=fklock
EMACS=t
COMMAND_MODE=unix2003
SSH_AUTH_SOCK=/tmp/launch-nbut32/Listeners
TERMCAP=
Apple_Ubiquity_Message=/tmp/launch-ffp7Xs/Apple_Ubiquity_Message
__CF_USER_TEXT_ENCODING=0x1F5:0:0
COLUMNS=80
PATH=/usr/bin:/bin:/usr/sbin:/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin
PWD=/Users/fklock/Dev/Mozilla/iontrail.git/objdir-js
EDITOR=~/bin/emacsclient
EMACSLOADPATH=/Applications/Emacs.app/Contents/Resources/site-lisp:/Applications/Emacs.app/Contents/Resources/lisp:/Applications/Emacs.app/Contents/Resources/leim
SHLVL=0
HOME=/Users/fklock
LOGNAME=fklock
INFOPATH=/Applications/Emacs.app/Contents/Resources/info:
DISPLAY=fklock-Oenone.local
INSIDE_EMACS=24.2.1,comint
SECURITYSESSIONID=186a6
EMACSDOC=/Applications/Emacs.app/Contents/Resources/etc
LINES=24
IONFLAGS=pararr
PAFLAGS=full
(gdb) r
Starting program: /Users/fklock/Dev/Mozilla/iontrail.git/objdir-js/js 
js> (new ParallelArray([4])).map(function (x) { return function () { return x+x } }, {mode: "par", expect: "success" })
(new ParallelArray([4])).map(function (x) { return function () { return x+x } }, {mode: "par", expect: "success" })
[pa] typein:1: newtype: [0x103f082b0]
[pa] typein:1: newtype: [0x103f08310]
[pa] typein:1: parallel map: attempting execution
[pa] typein:1: map: attempting parallel compilation
[pa] typein:1: warming up map with 1 iters
[ParallelArray] ParallelArray invoked with safe fn

[pa] typein:1: map: entering parallel section
[pa] typein:1: parallel map: success
({0:(function () { return x+x })})
js> (new ParallelArray([4])).map(function (x) { return function () { return x+x } }, {mode: "par", expect: "success" })
(new ParallelArray([4])).map(function (x) { return function () { return x+x } }, {mode: "par", expect: "success" })
[pa] typein:2: newtype: [0x103f083a0]
[pa] typein:2: newtype: [0x103f08400]
[pa] typein:2: parallel map: attempting execution
[pa] typein:2: map: attempting parallel compilation
[pa] typein:2: warming up map with 1 iters
[ParallelArray] ParallelArray invoked with safe fn

[pa] typein:2: map: entering parallel section
[pa] typein:2: parallel map: success
({0:(function () { return x+x })})
js> (new ParallelArray([4])).map(function (x) { return function () { return x+x } }, {mode: "par", expect: "success" })
(new ParallelArray([4])).map(function (x) { return function () { return x+x } }, {mode: "par", expect: "success" })
[pa] typein:3: newtype: [0x103f08490]
[pa] typein:3: newtype: [0x103f084f0]
[pa] typein:3: parallel map: attempting execution
[pa] typein:3: map: attempting parallel compilation
[pa] typein:3: warming up map with 1 iters
[ParallelArray] ParallelArray invoked with safe fn

typein:3:5 Error: expected success for parallel execution, got disqualified
js>