How to build Grafana-loki helm package from given repo

I m trying to build grafana-loki helm package in my local system after cloning code from repo - GitHub - grafana/loki: Like Prometheus, but for logs.
Basically I executed helm package command under folder loki/production/helm but getting error -

C:\Windows\System32\loki\production\helm>helm package loki                                                            
  Error: found in Chart.yaml, but missing in charts/ directory: minio, grafana-agent-operator  

Can anyone guide me or help me on this issue ?
How we can build chart in local after cloning this repo.