There are tests in our jstests/multiVersion directory that need to specify the binary version for replica sets starting with the ReplSetTest fixture. Some of these tests use the parameter `nodeOpts` as the field name for the options object, such as here or here.

'nodeOpts' as actually an invalid field name. The ReplSetTest fixture expects 'nodeOptions' instead, such as here. The reason these tests aren't failing is because every current usage of 'nodeOpts' tries to set the binary version to latest, and even though the parameter is completely ignored, the node defaults to starting in the latest binary.