Unexpectedly failed to find anchor for

Error message

Unexpectedly failed to find anchor for {rn} to make it a dependent branch

What it means

In the apply flow's `else` branch, the anchor reference needed to turn an incoming remote branch into a dependent branch could not be found in the workspace graph, which the code considers impossible ('Unexpectedly'). The apply aborts rather than misplacing the branch.

Solutions

Ensure the anchor branch referenced by the workspace still exists; restore it if deleted
Recompute/refresh the workspace and metadata, then retry apply
File a bug with reproduction if the state appears consistent

Defensive patterns

Strategy: try-catch

Validate before calling

// confirm the anchor branch for the incoming remote branch is applied
if !workspace_has_ref(&ws, &anchor_ref) {
    return Err("anchor branch not applied; apply it first");
}

Try / catch

match apply(...) {
    Err(e) if e.to_string().contains("failed to find anchor") => { refresh_workspace_and_retry(); }
    Err(e) => return Err(e.into()),
    Ok(r) => r,
}

Prevention

Ensure anchor branches referenced by adhoc workspaces still exist
Recompute workspace state after any manual branch deletion
File a bug with a reproduction if the state looks consistent

When it happens

Trigger: Applying a branch into an adhoc workspace when the computed anchor reference for the dependent-branch insertion is absent from the workspace graph/metadata.

Common situations: Workspace graph computed from an older state than the metadata; anchor branch was deleted concurrently; bug in adhoc-workspace handling.

Understand the failure class

Background: "This is a bug, please report it": internal invariant violations, unreachable panics, and SNH errors explained — this error's family across 47 libraries.

Related errors

AI-assisted analysis of gitbutlerapp/gitbutler@58e5313667 (2026-09-18). Data as JSON: /api/errors/1d8dc0737625d3bf. Report an issue: GitHub.

Appendix: source

Thrown at crates/but-workspace/src/branch/apply.rs:702

                        );
                    }
                    Some(false) => {
                        // The branch already existed, probably as stack, but it didn't come through. Remove it and use the anchor.
                        ws_mut.remove_segment(rn.as_ref());
                        if ws_mut.insert_new_segment_above_anchor_if_not_present(
                            rn.as_ref(),
                            segment_to_insert_above,
                        ) != Some(true)
                        {
                            bail!(
                                "Failed to assure that {rn} is in the workspace as dependent branch after removing it"
                            );
                        }
                    }
                    Some(true) => {}
                }
            } else {
                bail!("Unexpectedly failed to find anchor for {rn} to make it a dependent branch")
            }
        }

        // Redo the merge, with the different stack configuration.
        // Note that this is the exception, typically using stacks will be fine.
        let existing_stacks_superseded_by_branch =
            find_superseded_stacks(branch.as_ref(), &ws, &mut ws_md);
        merge_result = WorkspaceCommit::from_new_merge_with_metadata(
            filter_superseded_metadata_stacks(
                ws_md.stacks.iter(),
                &existing_stacks_superseded_by_branch,
            ),
            filter_superseded_anon_stacks(
                anon_stacks(&ws.stacks),
                &existing_stacks_superseded_by_branch,
            ),
            &ws.graph,
            &in_memory_repo,

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