The set_feature_compatibility_version.js test on the 3.6 branch creates scenarios in which servers are expected to fail or error, such as starting up without a featureCompatibilityVersion document and having a 3.4 binary version node in an FCV 3.6 replica set. Failures of this test are thus more difficult to diagnose because expected errors can be confused for unexpected errors. The test should log when it's about to perform an operation that is expected to fail to disambiguate expected errors from actual bugs. As of
SERVER-32909, the start up failure portions of the test in master have been separated into their own file.