We run out of space of chromeos images from time to time, and everybody things the error logs are showing that the builder is out of space, not the image.

Making it easier to see that the image is out of space would help sheriffs and developers respond more effectively.

Example:

https://luci-milo.appspot.com/buildbot/chromeos/chell-chrome-pfq/862

https://luci-logdog.appspot.com/v/?s=chromeos%2Fbb%2Fchromeos%2Fchell-chrome-pfq%2F862%2F%2B%2Frecipes%2Fsteps%2FBuildImage%2F0%2Fstdout


telemetry-0.0.1-r6:  * Removing /usr/share/man
telemetry-0.0.1-r6:  * Removing /usr/share/info
telemetry-0.0.1-r6:  * Removing /usr/share/doc
telemetry-0.0.1-r6:  * Running stacked hooks for pre_pkg_preinst
telemetry-0.0.1-r6:  *    wrap_old_config_scripts ...
telemetry-0.0.1-r6:  [ ok ]
telemetry-0.0.1-r6: !!! copy /build/chell/tmp/portage/chromeos-base/telemetry-0.0.1-r6/image/usr/local/telemetry/src/data/page_cycler/moz/www.voodooextreme.com/res/images_front_news_bottom_bg.gif -> /mnt/host/source/src/build/images/chell/R62-9830.0.0-rc2/rootfs/usr/local/usr/local/telemetry/src/data/page_cycler/moz/www.voodooextreme.com/res/images_front_news_bottom_bg.gif failed.
telemetry-0.0.1-r6: !!! [Errno 28] No space left on device
telemetry-0.0.1-r6: Exception IOError: IOError(28, 'No space left on device') in <bound method atomic_ofstream.__del__ of <_io.TextIOWrapper name='/mnt/host/source/src/build/images/chell/R62-9830.0.0-rc2/stateful/var_overlay/db/pkg/chromeos-base/-MERGING-telemetry-0.0.1-r6/CONTENTS.14172' encoding='utf_8'>> ignored
telemetry-0.0.1-r6: >>> Failed to install chromeos-base/telemetry-0.0.1-r6 to /mnt/host/source/src/build/images/chell/R62-9830.0.0-rc2/rootfs/usr/local/, Log file:
telemetry-0.0.1-r6: >>>  '/build/chell/tmp/portage/logs/chromeos-base:telemetry-0.0.1-r6:20170811-062319.log'