[louisabraham]

go vet ./... reports four calls to t.Fatal/t.Fatalf from a goroutine other than the test's:

sqlitex/savepoint_test.go:350:4: call to (*testing.T).Fatalf from a non-test goroutine
sqlitex/pool_test.go:202:4: call to (*testing.T).Fatal from a non-test goroutine
blob_test.go:218:5: call to (*testing.T).Fatal from a non-test goroutine
blob_test.go:237:6: call to (*testing.T).Fatalf from a non-test goroutine

t.Fatal calls runtime.Goexit, which only stops the goroutine that calls it. From another goroutine it does not stop the test, and testing documents that it must not be called there. Each call is replaced with t.Error/t.Errorf, followed by return where the goroutine must stop.

In pool_test.go, the goroutine still closes done after a failed Step. Before this change, a failure there skipped close(done).

Checked: go vet ./... reports nothing, and go test -race ./... passes.