How can I create a mirror of a private Terraform registry

We have a private Terraform registry hosted in Artifactory that mirrors providers from registry.terraform.io, but also has custom providers that will not be published to registry.terraform.io.

I opened a PR to create a “mirror of a mirror”. It does what I need. It works, but the PR was rejected.

So is there a another solution?

For clarity: I want to create a filesystem mirror of myprivateregistry.company.com

Terraform CLI does not currently allow you to do that.