Error during conversion to --development-rich-root

[Panagiotis Papadakos]

I get the following error when I try to upgrade my branch to latest --
development-rich-root:
starting upgrade of file:///home/mythos/Documents/University/Mitos/mitos/mitos-
devel/
making backup of file:///home/mythos/Documents/University/Mitos/mitos/mitos-
devel/.bzr
  to file:///home/mythos/Documents/University/Mitos/mitos/mitos-
devel/backup.bzr
starting repository conversion
bzr: ERROR: Must end write group before releasing write lock on 
CHKInventoryRepository('file:///home/mythos/Documents/University/Mitos/mitos/mitos-
devel/.bzr/repository/')

Original branch:
Format:
       control: Meta directory format 1
  working tree: Working tree format 4
        branch: Branch format 7
    repository: Packs 6 rich-root (uses btree indexes, requires bzr 1.9)