Function onStderr

integrations/utils.ts:332–337

(predicate: (message: string) => boolean)

              })
            },
            onStderr(predicate: (message: string) => boolean) {
              return new Promise<void>((resolve) => {
                stderrActors.push({ predicate, resolve })
                notifyNext(stderrActors, stderrMessages)
              })
            },
          }
        },
        fs: {