Unable to update registryurl for rust-version

[RonaldPhilipsen]

How are you running Renovate?

Self-hosted Renovate CLI

Which platform you running Renovate on?

GitHub Enterprise Server

Which version of Renovate are you using?

44.3.1

Please tell us more about your question or problem

I'm running renovate in an Airgapped environment. We've got secure mirrors for all upstream projects.
I'd like to be able to set a custom registry for all datasources.

Logs (if relevant)

Logs

{
  "name": "renovate",
  "hostname": "renovate-gh-281dbc79l2wqt-k6xdm",
  "pid": 95,
  "level": 40,
  "logContext": "22863f70-eef4-4ba7-b42e-da45ca79c021",
  "repository": "org/repo-test",
  "datasource": "rust-version",
  "registryUrls": [
    "https://artifactory.example.tld/artifactory/static.rust-lang.org/"
  ],
  "defaultRegistryUrls": null,
  "msg": "Custom registries are not allowed for this datasource and will be ignored",
  "time": "2026-08-14T11:47:34.873Z",
  "v": 0,
  "trace_id": "9226585f37c9006404629d43d3744bc1",
  "span_id": "55bb50c9b4265fe9",
  "trace_flags": "01"
}

[jamietanna]

We've got a feature request out for it: #45031

PR welcome!