Most of the canary waterfall builders are failing in the Archive stage, with an unbound variable error, something like this:

 INFO: RunCommand: /b/cbuild/repository/chromite/bin/cros_sdk 'USE=-cros-debug chrome_internal' 'PARALLEL_EMERGE_STATUS_FILE=/tmp/tmpAkOPjI' -- ./mod_image_for_recovery.sh '--board=chell' '--image=/mnt/host/source/src/build/images/chell/R59-9461.0.0/tmp59GXLC/chromiumos_base_image.bin' in /b/cbuild/repository
06:30:24: ERROR: 
return code: 1; command: /b/cbuild/repository/chromite/bin/cros_sdk 'USE=-cros-debug chrome_internal' 'PARALLEL_EMERGE_STATUS_FILE=/tmp/tmpAkOPjI' -- ./mod_image_for_recovery.sh '--board=chell' '--image=/mnt/host/source/src/build/images/chell/R59-9461.0.0/tmp59GXLC/chromiumos_base_image.bin'
 * Generating locale-archive: forcing # of jobs to 1
./mod_image_for_recovery.sh: line 82: PARTITION_NUM_STATE: unbound variable
mount: wrong fs type, bad option, bad superblock on /dev/loop2,
       missing codepage or helper program, or other error

       In some cases useful info is found in syslog - try
       dmesg | tail or so.
cp: cannot stat ‘/tmp/tmp.9vgM6K5w1p/vmlinuz_hd.vblock’: No such file or directory
umount: /tmp/tmp.9vgM6K5w1p: not mounted
./mod_image_for_recovery.sh: line 101: PARTITION_NUM_ROOT_A: unbound variable
./mod_image_for_recovery.sh: line 102: PARTITION_NUM_ROOT_A: unbound variable
grep: /mnt/host/source/src/build/images/chell/R59-9461.0.0/tmp59GXLC/boot.desc: No such file or directory
./mod_image_for_recovery.sh: line 119: PARTITION_NUM_KERN_A: unbound variable
./mod_image_for_recovery.sh: line 120: PARTITION_NUM_KERN_A: unbound variable 
dd: invalid number: ‘’
?

cbuildbot --remote jobs are also failing in this manner.