Cas Commit Refs

cas — Commit SHAs accepted in ref=

Source URLs of the form git::<url>?ref=<commit-sha> now resolve through CAS. Previously these clones failed because Terragrunt asked the remote to look up the SHA as a symbolic reference, which Git servers don't support.

Both full SHAs (SHA-1 and SHA-256) and abbreviated SHAs are accepted. Abbreviated SHAs must disambiguate inside the repository, the same rule Git itself applies.

terraform {
  source = "git::https://github.com/acme/infrastructure-modules.git//vpc?ref=a1b2c3d4e5f67890abcdef1234567890deadbeef"
}

The first cold clone of a repository pinned to a commit SHA fetches the full history of every branch. Shallow fetches require a ref name, and fetching a commit SHA at limited depth depends on a server option (uploadpack.allowAnySHA1InWant) that is not universally enabled, so CAS fetches all branches at full depth and resolves the SHA locally. Subsequent clones reuse the cached repository and never touch the network for the same commit. Branch and tag refs continue to use the existing shallow path.