Failed to assure that

Error message

Failed to assure that {rn} is in the workspace as dependent branch after removing it

What it means

After removing a conflicting segment, apply re-inserts the branch as a dependent branch above an anchor and requires `insert_new_segment_above_anchor_if_not_present` to return `Some(true)`. Any other result means the branch could not be established as a dependent branch, so apply fails to leave the workspace in a defined state.

Solutions

Rebuild workspace metadata from the repository state and retry the apply
Retry the apply operation once metadata is consistent (no concurrent writers)
If reproducible, file a bug — this indicates the insert helper failed unexpectedly after a successful remove

Defensive patterns

Strategy: try-catch

Try / catch

match apply(...) {
    Err(e) if e.to_string().contains("as dependent branch after removing") => { rebuild_workspace(); retry(); }
    Err(e) => return Err(e.into()),
    Ok(r) => r,
}

Prevention

Avoid concurrent operations on the same workspace
Refresh workspace state before applying into adhoc workspaces
Report reproducible failures as upstream bugs

When it happens

Trigger: Apply flow on an adhoc workspace where, after `remove_segment`, the anchor for re-insertion is not found or the insert reports the branch still not added — a race between the removal and insertion or missing anchor in metadata.

Common situations: Same class as error 352: stale/incorrect workspace metadata during adhoc workspace apply, or a bug in the segment bookkeeping.

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/9a9977f4d527e81f. Report an issue: GitHub.

Appendix: source

Thrown at crates/but-workspace/src/branch/apply.rs:694

                match ws_mut.insert_new_segment_above_anchor_if_not_present(
                    rn.as_ref(),
                    segment_to_insert_above,
                ) {
                    None => {
                        // For now bail, until we know it's worth fixing this case automatically.
                        bail!(
                            "Missing reference {segment_to_insert_above} which should be known to workspace metadata to serve as insertion position for {rn}"
                        );
                    }
                    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(),

View on GitHub (pinned to 58e5313667)