SERVER-102818 added a suite that automatically add and remove shards while running tests. agg_lookup.js performs an aggregation with a $lookup which can fail if the query is executed while removing a shard. Note that this error is not retryable in this context, as the query may need getMores to get the result set. and they can't be retried (this is reflected in jstests/libs/override_methods/implicitly_retry_on_shard_transition_errors.js, which is included in this suite).

There are two ways of solving this, by either tagging the test as not compatible with suites that add and remove shards in the background, or by accepting the ShardNotFound error if we are running those types of suites.