combo-layer: handle unset dest_dir in sanity_check()
The previous "clean up dest_dir checking" patch (
f8cdbe7497) improved
handling of empty dest_dir but made handling of unset dest_dir worse:
instead showing the "Option dest_dir is not defined for component ..."
error, it fails with a Python exception.
Avoid that by providing a sane fallback for the unset case. With that
change, dest_dir is no longer strictly required, but the check for it
is kept to ensure that a combo-layer.conf also works with older
combo-layer versions.
[Yocto #7773]
Signed-off-by: Patrick Ohly <patrick.ohly@intel.com>
Signed-off-by: Ross Burton <ross.burton@intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
