What causes "get diffs: %w" in alibaba/open-code-review?

Run `git -C status` and `git rev-parse ` manually to reproduce the underlying git error.

get diffs: %w

Error message

get diffs: %w

What it means

loadDiffs obtains the diff via a provider (commit, range, or workspace) and wraps any provider.GetDiff failure with this message. The error means the git-level diff computation failed before any review work started: git itself errored, the repository/refs do not exist, or the context was cancelled.

Source

Thrown at internal/agent/agent.go:546

		case commit != "":
			commit = s.ResolvedHead
		case s.ResolvedBase != "":
			from, to = s.ResolvedBase, s.ResolvedHead
		}
	}

	switch {
	case commit != "":
		provider = diff.NewCommitProvider(a.args.RepoDir, commit, a.args.GitRunner)
	case from != "" && to != "":
		provider = diff.NewProvider(a.args.RepoDir, from, to, a.args.GitRunner)
	default:
		provider = diff.NewWorkspaceProvider(a.args.RepoDir, a.args.GitRunner)
	}

	parsed, err := provider.GetDiff(ctx)
	if err != nil {
		return fmt.Errorf("get diffs: %w", err)
	}

	a.diffs = parsed

	// Freeze this run's real commit endpoints and repository identity while the
	// git-backed provider and a live context are in hand; finalizeManifest reads
	// these (never re-resolving) so the manifest records the input as it was at
	// dispatch time, even on a later skipped or failed path.
	a.inputResolution = provider.ResolveInput(ctx)
	a.repoRemoteIdentity = provider.RemoteIdentity(ctx)

	for i := range parsed {
		d := &parsed[i]
		a.totalInsertions += d.Insertions
		a.totalDeletions += d.Deletions
	}

	return nil

View on GitHub (pinned to 5cf97d0d15)

Solutions

Run `git -C <RepoDir> status` and `git rev-parse <ref>` manually to reproduce the underlying git error.
Verify the commit/range refs exist and the repo is a valid clone (fetch missing refs if shallow).
Confirm RepoDir points at the repository root and git is on PATH.
For workspace mode, ensure there are readable worktree changes and the index is not locked (.git/index.lock).

Example fix

// before: 'get diffs: exit status 128 - fatal: bad revision main..feat/x'
ocr review --from main --to featx   // typo
// after
ocr review --from main --to feat/x  // correct ref, after `git fetch origin`

Defensive patterns

Strategy: validation

Validate before calling

// validate repo and refs before calling Run
cmd := exec.Command("git", "-C", repoDir, "rev-parse", "--verify", ref)
if err := cmd.Run(); err != nil { return fmt.Errorf("ref %s missing in %s", ref, repoDir) }
// and confirm it is a work tree:
exec.Command("git", "-C", repoDir, "rev-parse", "--is-inside-work-tree").Run()

Prevention

Always fetch the base branch in CI (shallow clones need git fetch --depth or unshallow for range diffs).
Validate commit/range arguments with git rev-parse before invoking the tool.
Run the tool with RepoDir set to the repository root.
Ensure git is installed and GIT_* env vars don't redirect to another repository.

When it happens

Trigger: Agent.Run() or ResolveIdentity() with a RepoDir that is not a git repository; --commit or --from/--to refs that do not resolve; an empty repository; git binary missing; context cancelled during GetDiff.

Common situations: Typo in a commit SHA or branch name; running outside a repo; shallow clone missing the requested ref; detached CI checkout lacking the base branch; GIT_DIR/GIT_WORK_TREE env conflicts; git not installed in the container.

Related errors

AI-assisted analysis of alibaba/open-code-review@5cf97d0d15 (2026-09-02). Data as JSON: /api/errors/e2a308bbd1ebd133. Report an issue: GitHub.