As with the previous similar changes, this is intended to catch
problems as they happen instead of ignoring them and continuing on
to potentially fail later. Setting this on all existing scripts
will allow us to enforce use via Jenkins.
Change-Id: Iad2d490c86dceab148ea9ab08f457c49a5d5352e
Commit c7d80dd (Cleanup mount points automatically) removed the unmount
of $TMP_MOUNT_PATH/tmp/ccache in run_d_in_target() and moved the
"rm /tmp/ccache" to elements/base/finalise.d/02-remove-ccache. There
are two problems with this:
1) Not unmounting at the end of run_d_in_target() results in tmp/ccache
being bind mounted muliple times on top of itself (three times, if you
just run `disk-image-create base`). It is eventually unmounted, but
somehow the auto unmount code is confused, and tries to unmount it
one more time than it was mounted, which results in an error like
"umount: /tmp/image.THQkZxQa/mnt/tmp/ccache: not mounted".
This doesn't actually break anything, but it's a little messy.
2) "rm /tmp/ccache" in elements/base/finalise.d/02-remove-ccache never
succeeds in removing /tmp/ccache, because that hook is invoked by
run_d_in_target(), *while* /tmp/ccache is mounted.
This present commit solves the above by moving the ccache setup glue out
of img-functions and into the base element's root.d. This has the
following implications:
1) lib/img-functions is a little cleaner.
2) /tmp/ccache is available in the chroot during the root, extra-data,
pre-install, install and post-install stages. It is not available
during block-device, finalise and cleanup stages as it will have been
automatically unmounted by then.
3) /tmp/ccache won't be setup if you're building an image that doesn't
include the base element.
Change-Id: Ief4c0a6f4ec622db6c6f652776215684178d8943
