The failure was spotted here https://github.com/eclipse-vertx/vertx-sql-client/actions/runs/14066854373/job/39392270396
It appears it happens if this CloseConnectionTest is the first test in the suite or if CloseConnectionTest#testTransactionInProgressShouldFail is the only test executed.
Debugging showed that the issue appeared after VertxConnection changes in core: eclipse-vertx/vert.x@40bdf1e
Reverting this commit makes the test pass again.
In a few words, when the rollback command is sent to the connection, the event is added to the pending list, but never handled.
As agreed off-list, I'll disable this test temporarily