error occurred when no parser specified for run-custom command

When not specified parser option for run-custom command, it would report "Invalid regular expression 'None' - first argument must be string or compiled pattern" error

(latest)18:01:27 liuyq:tmp$ /srv/lava/instances/latest/bin/lava-android-test run-custom -f http://bazaar.launchpad.net/~linaro-validation/lava-android-test/trunk/download/head:/busybox_test.sh-20110927085925-2fxzf7wrrtq4gci0-3/busybox_test.sh -s 192.168.1.150:5555 -o /tmp/tmpI1hjYt/custom.2012-03-22T09:48:24Z.bundleLAVA: --Start Operation: Run following custom test(s) on device(192.168.1.150:5555):
 commands=chmod 777 /data/lava-android-test/share/installed-tests/custom/busybox_test.sh
  /data/lava-android-test/share/installed-tests/custom/busybox_test.sh
 command-file=busybox_test.sh

LAVA: Begin to execute command: wget http://bazaar.launchpad.net/~linaro-validation/lava-android-test/trunk/download/head:/busybox_test.sh-20110927085925-2fxzf7wrrtq4gci0-3/busybox_test.sh -O busybox_test.sh
LAVA: (stdout) --2012-03-22 18:01:33-- http://bazaar.launchpad.net/~linaro-validation/lava-android-test/trunk/download/head:/busybox_test.sh-20110927085925-2fxzf7wrrtq4gci0-3/busybox_test.sh
LAVA: (stdout) Resolving bazaar.launchpad.net... 91.189.90.11
LAVA: (stdout) Connecting to bazaar.launchpad.net|91.189.90.11|:80... connected.
LAVA: (stdout) HTTP request sent, awaiting response... 200 OK
LAVA: (stdout) Length: 833 [text/x-sh]
LAVA: (stdout) Saving to: `busybox_test.sh'
LAVA: (stdout)
LAVA: (stdout) 0K 100% 5.26M=0s
LAVA: (stdout)
LAVA: (stdout) 2012-03-22 18:01:35 (5.26 MB/s) - `busybox_test.sh' saved [833/833]
LAVA: (stdout)
LAVA: Begin to execute command: adb -s 192.168.1.150:5555 push busybox_test.sh /data/lava-android-test/share/installed-tests/custom/busybox_test.sh
LAVA: (stdout) 20 KB/s (833 bytes in 0.040s)
LAVA: Begin to execute command: adb -s 192.168.1.150:5555 shell chmod 777 /data/lava-android-test/share/installed-tests/custom/busybox_test.sh
LAVA: Begin to execute command: adb -s 192.168.1.150:5555 shell /data/lava-android-test/share/installed-tests/custom/busybox_test.sh
LAVA: (stdout) mkdir=pass
LAVA: (stdout) touch=pass
LAVA: (stdout) ls=pass
LAVA: (stdout) ps=pass
LAVA: (stdout) whoami=pass
LAVA: (stdout) which=pass
LAVA: (stdout) basename=pass
LAVA: (stdout) cp=pass
LAVA: (stdout) rm=pass
LAVA: (stdout) dmesg=pass
LAVA: (stdout) grep=pass
ANDROID TEST RUN COMPLETE: Result id is 'custom1332381692.0'
ERROR: Test execution error: AndroidTestParser - Invalid regular expression 'None' - first argument must be string or compiled pattern
(latest)18:01:44 liuyq:tmp$