def test_upgrade_5_critical_error(self):
        """Test the migration from version 5 with a critical error."""
        # build a fake version 5 state
        self._build_layout_version_4()
        self.set_md_version('5')
        # create some old shares and shared metadata
        legacy_shares = LegacyShareFileShelf(self.share_md_dir)
        root_share = _Share(path=self.root_dir, share_id=request.ROOT,
                            access_level=ACCESS_LEVEL_RW)
        legacy_shares[request.ROOT] = root_share
        for idx, name in enumerate(['share'] * 10):
            sid = str(uuid.uuid4())
            share_name = name + '_' + str(idx)
            share = _Share(path=os.path.join(self.shares_dir, share_name),
                           share_id=sid, name=share_name,
                           node_id=str(uuid.uuid4()),
                           other_username='******' + str(idx),
                           other_visible_name='visible name ' + str(idx))
            if idx % 2:
                share.access_level = ACCESS_LEVEL_RW
            else:
                share.access_level = ACCESS_LEVEL_RO
            legacy_shares[sid] = share
        # create shared shares
        legacy_shared = LegacyShareFileShelf(self.shared_md_dir)
        for idx, name in enumerate(['dir'] * 5):
            sid = str(uuid.uuid4())
            share_name = name + '_' + str(idx)
            share = _Share(path=os.path.join(self.root_dir, share_name),
                           share_id=sid, node_id=str(uuid.uuid4()),
                           name=share_name, other_username='******',
                           other_visible_name='hola')
            if idx % 2:
                share.access_level = ACCESS_LEVEL_RW
            else:
                share.access_level = ACCESS_LEVEL_RO
            legacy_shared[sid] = share

        # keep a copy of the current shares and shared metadata to check
        # the upgrade went ok
        legacy_shares = dict(legacy_shares.items())
        legacy_shared = dict(legacy_shared.items())

        if self.md_version_None:
            self.set_md_version('')
        # upgrade it!
        old_upgrade_share_to_volume = MetadataUpgrader._upgrade_share_to_volume

        def upgrade_share_to_volume(share, shared=False):
            raise ValueError('FAIL!')
        MetadataUpgrader._upgrade_share_to_volume = upgrade_share_to_volume
        try:
            self.assertRaises(ValueError, FakeMain, self.root_dir,
                              self.shares_dir, self.data_dir,
                              self.partials_dir)
        finally:
            MetadataUpgrader._upgrade_share_to_volume = \
                    old_upgrade_share_to_volume

        shares = LegacyShareFileShelf(self.share_md_dir)
        self.assertEqual(len(list(shares.keys())), len(legacy_shares.keys()))
        for sid, share in shares.iteritems():
            old_share = legacy_shares[sid]
            self.assertTrue(isinstance(share, _Share))
            self.assertTrue(isinstance(old_share, _Share))
        shared = LegacyShareFileShelf(self.shared_md_dir)
        self.assertEqual(len(list(shared.keys())), len(legacy_shared.keys()))
        for sid, share in shared.iteritems():
            old_share = legacy_shared[sid]
            self.assertTrue(isinstance(share, _Share))
            self.assertTrue(isinstance(old_share, _Share))