failed to set data, cannot locate database file

When I try to run one of the spatial tests I always get a lot of warning like:

memcached<0.431.0>: Warning: failed to set data, cannot locate database file /home/vmx/src/couchbase/testrunner_2.0/ns_server/couch/0/default/752.couch

When I have a look at the directory, it turns out that the couch files have a number suffix. I guess that's where the problem is.

This blocks making the spatial tests pass.

To run the test, just run a 4 node cluster with
./cluster_run -n 4
(you can set COUCHBASE_NUM_VBUCKETS=256, to make it run faster).

Then go to the testrunner directory and run the testrunner test with:
./testrunner -i b/resources/dev-4-nodes.ini -t spatialrebalancetests.SpatialRebalanceTests.test_insert_x_docs_during_rebalance,num-docs=10000