构建步骤0“ gcr.io/google-appengine/exec-wrapper:latest”失败：退出状态1

Question

我正在尝试第一次将Rails应用程序部署到Google Cloud。决定尝试一下heroku。好吧，当尝试执行bundle exec rake appengine：exec-bundle exec rake db：migrate时，它开始迁移，但随后退出，并显示此错误：ERROR：build step 0“ gcr.io/google-appengine/exec-wrapper：最新”失败：退出状态1

这是我的database.yml的样子：

default: &default
  adapter: postgresql
  encoding: unicode
  # For details on connection pooling, see Rails configuration guide
  # http://guides.rubyonrails.org/configuring.html#database-pooling
  pool: <%= ENV.fetch("RAILS_MAX_THREADS") { 5 } %>

production:
  <<: *default
  database: postgres
  username: won't show
  password: won't show
  host: /cloudsql/books4reviews:us-central1:postgres-instance

我的app.yaml：

entrypoint: bundle exec rackup --port $PORT
env: flex
runtime: ruby

env_variables:
  SECRET_KEY_BASE: [secret_key_base]

beta_settings:
  cloud_sql_instances: books4reviews:us-central1:postgres-instance

如果还有其他需要包括的内容，请告诉我！