Job cancellation doesn't work in database/sql driver

Reproduce the issue with the SortWorker example, riverui's Cancel action, and riverdatabasesql.New using the described pgx and ocsql setup. Start by tracing cancellation from the cancel_attempted_at metadata to the Work context; done means the worker observes ctx.Done, logs CANCELLED, and stops before the 20-second delay.

Hi!

I am using the example SortWorker job with small adjustments to test longer-running jobs with cancellation but it does not seem to work.

const SortJobKind = "sort"

type SortArgs struct {
  Strings []string `json:"strings"`
}

func (SortArgs) Kind() string {
  return SortJobKind
}

type SortWorker struct {
  river.WorkerDefaults[SortArgs]
}

func (w *SortWorker) Work(ctx context.Context, job *river.Job[SortArgs]) error {
  log.Printf("STARTING: %d", job.ID)
  select {
  case <-ctx.Done():
    log.Printf("CANCELLED: %d", job.ID)
    return ctx.Err()
  case <-time.After(20 * time.Second):
    log.Printf("WILL DO: %d", job.ID)
  }

  items := job.Args.Strings
  sort.Strings(items)
  log.Printf("RESULT: %+v\n", items)
  return nil
}

When the job appears in the User Interface (riverui), I click Cancel but the job keeps running. In the logs I eventually get from STARTING to WILL DO but never observe CANCELLED.

The only thing that indicates some attempt at cancellation is the metadata field on the job which states:

{
  "cancel_attempted_at": "2024-10-02T....."
}

Am I doing something wrong or is there a potential bug?

I am running v0.12.1 and using riverdatabasesql.New, though the underlying connection is pgx, wrapped with opencensus tracing (ocsql).