The /transactions/legacy/pin-mongos/ JSON spec test currently fails and/or is flaky. The specific failure is in the "unpin after transient error within a transaction and commit" sub-test. The test failure is a result of server selection timeout.

The test is currently being skipped, so to work on it, it will first be necessary to remove it from .evergreen/skip-tests.txt and run a patch build to determine the current failure mode(s).