Cleanup failed after every logical assertion had passed

Macro’s order queue persists queued → claimed → awaiting_handoff/uncertain → terminal transitions and idempotency keys in SQLite. FIFO, duplicate prevention, and recovery tests passed on Linux, but the Windows job failed with WinError 32 when deleting its temporary orders.sqlite3 after the assertions completed.

The same job found two more assumptions: Korean diagnostic text raised UnicodeEncodeError on a cp1252 console, and a configuration test compared a POSIX-slash suffix that could not match a Windows path. The symptoms differed, but all three treated one development OS’s defaults as part of the contract.

A SQLite context manager manages a transaction, not the connection

Queue access used:

with sqlite3.connect(path) as connection:
    # query and update

The sqlite3.Connection context manager commits on success and rolls back on failure, but it does not close the connection. macOS and Linux either allow unlinking an open handle or hid the leak behind object-finalization timing. Windows prevented deletion while the file handle remained open.

The Python sqlite3 reference explicitly states that leaving the context does not close the connection.

Transaction and resource lifetime moved behind one seam

I routed every queue operation through a dedicated context manager that closes in finally:

@contextmanager
def open_queue(path):
    connection = sqlite3.connect(path)
    try:
        with connection:
            yield connection
    finally:
        connection.close()

I rejected cleanup sleeps and deletion retries because they would make tests pass while retaining a real handle leak. Removing WAL would weaken concurrent access without fixing ownership.

Tests now compare platform-independent meaning

Rather than remove Korean operational diagnostics, the CI jobs explicitly enable Python UTF-8 mode. Paths are verified through pathlib.Path.parts instead of replacing separators or comparing a slash-formatted string.

The full unittest suite and compileall passed again on macOS, followed by the same quality workflow on Ubuntu and Windows. Temporary databases became deletable immediately after the transaction, while Korean messages and path coverage remained intact. The troubleshooting record preserves the alternatives and impact boundary.

The value of cross-platform CI was not more OS-specific branches. One OS turned a lifecycle bug tolerated by another into a deterministic failure, and the fix repaired resource ownership instead of hiding cleanup symptoms.