euca-bundle-vol fails on when running tune_cmd

Binary package hint: euca2ools

Using the alpha1 oneiric UEC image + euca2ools 1.3.1-0ubuntu8, bundling no longer works for an ext4 root filesystem:
1.3.1-0ubuntu8

# euca-bundle-vol -u adam -s 8192 -e /mnt -e /tmp -k aki-7ff3f027 -r x86_64 -d /tmp -c novacred/cert.pem -k novacred/pk.pem --ec2cert novacred/cacert.pem -p oneiric_alpha1 --no-inherit
1+0 records in
1+0 records out
1048576 bytes (1.0 MB) copied, 0.00353191 s, 297 MB/s
mke2fs 1.41.14 (22-Dec-2010)
Filesystem label=uec-rootfs
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=0 blocks, Stripe width=0 blocks
524288 inodes, 2097152 blocks
104857 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=2147483648
64 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632

Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

This filesystem will be automatically checked every 32 mounts or
180 days, whichever comes first. Use tune2fs -c or -i to override.
Traceback (most recent call last):
  File "/usr/bin/euca-bundle-vol", line 493, in <module>
    main()
  File "/usr/bin/euca-bundle-vol", line 401, in main
    label=fsinfo['label'])
  File "/usr/lib/python2.7/dist-packages/euca2ools/__init__.py", line 1268, in make_image
    self.img.make_fs(image_path, fs_type=fs_type, uuid=uuid, label=label)
  File "/usr/lib/python2.7/dist-packages/euca2ools/__init__.py", line 250, in make_fs
    tune_cmd = Popen(tunecmd,PIPE).communicate[0]
TypeError: 'instancemethod' object is not subscriptable
tune2fs 1.41.14 (22-Dec-2010)