Earlier I was trying to debug a failure in the tenant_migration_donor_retry.js test which is marked as incompatible_with_shard_merge. I didn't realize that I was accidentally providing --additionalFeatureFlags featureFlagShardMerge in my local resmoke invocation (a habit because I had been running a lot of tests which require that feature flag recently), so when I ran the test locally I was getting a very different error than in my patch build. This feels like a class of error we should be able to catch programmatically.