Hi Vercel Community,

I'm trying to resolve a build issue with a private GitHub repository connected to Vercel.

Our release verification requires historical Git commits beyond Vercel's default shallow checkout, including commits from a separate rollback branch that is not an ancestor of the release commit.

Current situation

• Private GitHub repository connected through the official Vercel GitHub integration.
• Vercel's shallow checkout does not contain all commits needed by our release checks.
• The checks fail with fatal: bad object when historical commits are missing.
• The same checks and production build pass locally when both release and rollback histories are available.
• We want to preserve the existing release checks and verified Git commit provenance.

My questions

1. Can a Vercel Git-connected build use its existing GitHub integration to perform authenticated git fetch operations for additional history from a private repository, without a new personal access token, deploy key or other credential?
2. Can it fetch a separate, non-ancestor rollback branch as well as the release history?
3. If supported, what is the recommended approach—custom Build Command, install step, or another checkout configuration?
4. Does the same mechanism work for a staged Production redeployment with automatic Production domain assignment disabled?
5. If this is unsupported, is there a recommended way to provide complete Git history while retaining reliable source-commit verification?

We are trying to avoid weakening release verification or adding unnecessary credentials.

Any guidance or working examples would be appreciated. Thanks!