helmfile 缺少 repos 错误，如何修复？

Question

我已经创建了一个示例 helmfile.yaml，其内容如下。

releases:
  - name: loki-multitenant
    chart: ./loki
    namespace: default
    values:
      - loki-distributed:
          querier:
            replicas: 3
          loki:
            auth_enabled: true
            storageConfig:
              boltdb_shipper:
                shared_store: gcs
              gcs:
                bucket_name: loki-store-jr
            schemaConfig:
              configs:
                - from: 2020-07-01
                  object_store: gcs
            compactor:
              shared_store: gcs

以及 loki-multitenant 图表文件夹 loki 的内容。loki\Chart.yaml

apiVersion: v2
name: loki
description: A Helm chart for Kubernetes

type: application
version: 0.0.1

appVersion: "v0.0.1"

dependencies:
  - name: ingress-nginx
    version: 4.1.4
    repository: https://kubernetes.github.io/ingress-nginx

  - name: loki-distributed
    repository: https://grafana.github.io/helm-charts
    version: ^0.48.4

模板中还有一些虚拟内容，主要部分用于子依赖图表。

当我运行：helmfile sync

Building dependency release=loki-multitenant, chart=loki
in ./helmfile.yaml: [building dependencies of local chart: command "/usr/local/bin/helm" exited with non-zero status:

PATH:
  /usr/local/bin/helm

ARGS:
  0: helm (4 bytes)
  1: dependency (10 bytes)
  2: build (5 bytes)
  3: loki (4 bytes)

ERROR:
  exit status 1

EXIT STATUS
  1

STDERR:
  Error: no repository definition for https://kubernetes.github.io/ingress-nginx, https://grafana.github.io/helm-charts. Please add the missing repos via 'helm repo add'

COMBINED OUTPUT:
  Error: no repository definition for https://kubernetes.github.io/ingress-nginx, https://grafana.github.io/helm-charts. Please add the missing repos via 'helm repo add']

所以我尝试跑步

helm dependency update loki/

将 tar.gz 文件下载到 loki/charts 文件夹。

loki/charts$ ls
ingress-nginx-4.1.4.tgz  loki-distributed-0.48.6.tgz

但 helmfile sync 仍然出现相同错误。请建议如何修复此问题。