pre-commit "The unauthenticated git protocol ... is no longer supported" in CI

By Daniel Zoghalchali·Latchkey

pre-commit cloned a hook repo using the plain git:// protocol and the host now refuses it. GitHub disabled the unauthenticated git protocol, so the fetch fails while setting up the hook.

What this error means

Setting up a hook repo fails with "The unauthenticated git protocol on port 9418 is no longer supported" during the clone step of pre-commit env setup.

fatal: unable to access 'git://github.com/owner/hook-repo/':
The unauthenticated git protocol on port 9418 is no longer supported.

Common causes

A hook repo URL uses git:// instead of https://

The repo: in the config, or a global git insteadOf rule, forces the unauthenticated protocol GitHub has disabled.

A git insteadOf rewrite maps https to git protocol

A url.git://.insteadOf config on the runner rewrites clone URLs to the retired protocol.

How to fix it

Use https for hook repos

1. Change any git:// repo URLs in the config to https://.
2. Remove any insteadOf rule that forces the git protocol.
3. Re-run so the clone uses https.

- repo: https://github.com/owner/hook-repo
  rev: v1.2.0
  hooks:
    - id: my-hook

Rewrite git protocol to https at the git layer

If a hook repo hardcodes the old protocol, add a global rewrite to https.

git config --global url."https://github.com/".insteadOf "git://github.com/"

How to prevent it

• Always reference hook repos over https.
• Avoid insteadOf rules that map to the git protocol.
• Cache PRE_COMMIT_HOME so hook repos are cloned once.

Frequently asked questions

Related guides

References

• GitHub Actions documentation