In bug 842899, /data is running out of disk space during a variety of tests. It looks like xpcshell tests are to blame. :jmaher found these files on one tegra that had very little space left on /data: jmaher@x230:~$ adb shell ls -l /data/local/xpcb -rwxrwxrwx app_31 app_31 21552 2013-05-13 16:16 libomxplugingb.so -rwxrwxrwx app_31 app_31 22268 2013-05-13 16:16 libomxpluginjb-htc.so -rwxrwxrwx app_31 app_31 21556 2013-05-13 16:16 libomxplugingb235.so -rwxrwxrwx app_31 app_31 21575 2013-05-13 16:16 libomxpluginfroyo.so -rwxrwxrwx app_31 app_31 51491554 2013-05-13 16:15 libxul.so -rwxrwxrwx app_31 app_31 22172 2013-05-13 16:16 libomxplugin.so -rwxrwxrwx app_31 app_31 2092625 2013-05-13 16:15 libnss3.so -rwxrwxrwx app_31 app_31 21580 2013-05-13 16:16 libomxpluginhc.so -rwxrwxrwx app_31 app_31 498708 2013-05-13 16:16 libnssckbi.so -rwxrwxrwx app_31 app_31 13327 2013-05-13 16:16 libplugin-container.so -rwxrwxrwx app_31 app_31 506015 2013-05-13 16:16 libmozglue.so -rwxrwxrwx app_31 app_31 495 2013-05-13 16:20 xpcw drwxrwxrwx app_31 app_31 2013-04-08 12:09 defaults -rwxrwxrwx app_31 app_31 29047713 2013-05-13 16:15 fennec-24.0a1.en-US.android-arm.apk -rwxrwxrwx app_31 app_31 22418 2013-05-13 16:16 libomxpluginsony.so -rwxrwxrwx app_31 app_31 25186732 2013-05-13 15:16 fennec-24.0a1.en-US.android-arm-armv6.apk -rwxrwxrwx app_31 app_31 731229 2013-05-13 16:15 xpcshell -rwxrwxrwx app_31 app_31 28945697 2013-05-10 06:18 fennec-23.0a1.en-US.android-arm.apk -rwxrwxrwx app_31 app_31 287001 2013-05-13 16:16 libfreebl3.so -rwxrwxrwx app_31 app_31 217962 2013-05-13 16:16 libsoftokn3.so -rwxrwxrwx app_31 app_31 13773 2013-05-13 16:15 libmozalloc.so -rwxrwxrwx app_31 app_31 25183797 2013-05-13 05:58 fennec-23.0a1.en-US.android-arm-armv6.apk (talos)jmaher@x230:~$

Notice especially that there are 4 apks, 3 of which have older timestamps than the other files. I suspect nothing is deleting /data/local/xpcb and each xpcshell test run has the potential for adding files there.

Probably best to just do this in the cleanup step...