vendors/execa.js/getSpawnedPromise
var getSpawnedPromise = (spawned) => new Promise((resolve, reject) => {
  spawned.on("exit", (exitCode, signal) => {
    resolve({ exitCode, signal });
  });
  spawned.on("error", (error) => {
    reject(error);
  });
  if (spawned.stdin) {
    spawned.stdin.on("error", (error) => {
      reject(error);
    });
  }
});