gitbutlerapp/gitbutler · warning · anyhow::Error

Cannot comment on {scope}: the diff is binary or too large

Error message

Cannot comment on {scope}: the diff is binary or too large

What it means

create_comment() classified the file as FileAnchor::Unanchorable: the diff for {scope} is binary or exceeds the size threshold the diff machinery allows, so no line model exists and line comments are impossible by design.

Source

Thrown at crates/but-comments/src/lib.rs:140

    workspace: &but_graph::Workspace,
    store: &CommentStore,
    comment: NewComment,
    context_lines: u32,
    now_ms: i64,
) -> anyhow::Result<DiffComment> {
    let scope = anchor_scope_display(&comment.commit_change_id, &comment.path);
    let mut diffs = ScopeDiffs::new(repo, workspace, context_lines);
    let Some(anchor) = diffs.file(comment.commit_change_id.as_deref(), &comment.path)? else {
        bail!(
            "Commit {} is not in the applied workspace",
            comment.commit_change_id.as_deref().unwrap_or_default()
        );
    };
    let file = match anchor {
        FileAnchor::Lines(lines) => lines,
        FileAnchor::Gone => bail!("Nothing to anchor a comment to in {scope}"),
        FileAnchor::Unanchorable => {
            bail!("Cannot comment on {scope}: the diff is binary or too large")
        }
    };
    let line = file
        .line_at(comment.side, comment.line_number)
        .with_context(|| {
            format!(
                "No line {} on the {} side in {scope}",
                comment.line_number,
                comment.side.as_str(),
            )
        })?;

    // Snapshot the same-side neighbouring lines too: they disambiguate between identical
    // lines when the comment is re-located later.
    let line_before = (comment.line_number > 1)
        .then(|| file.line_at(comment.side, comment.line_number - 1))
        .flatten()
        .map(|line| line.content.clone());

View on GitHub (pinned to caf1f223d3)

Solutions

1. Use a non-line-scoped comment (commit/file level) for that path instead
2. Mark the file binary or exclude it from review if it is generated output
3. Split the change so the file's diff fits under the size threshold
4. If the file is genuinely reviewable text, check .gitattributes rules that misclassify it (e.g. -diff)

// cheap pre-checks before offering line comments
let is_binary = std::fs::read(&path).is_ok_and(|b| b.contains(&0));
let too_large = std::fs::metadata(&path).map(|m| m.len() > MAX_REVIEWABLE).unwrap_or(true);
if is_binary || too_large { ui.disable_line_comments(&path); }

match create_comment(...) {
    Err(e) if e.to_string().contains("binary or too large") =>
        create_file_level_note(comment).await, // degrade, don't fail
    r => r?,
}

When it happens

Trigger: Attempting a line comment on a binary file (image, compiled artifact, lockfile marked binary) or a text file whose diff is too large for the anchored-diff representation.

Common situations: Reviewing generated files, vendored blobs, or minified bundles; large SQL/CSV data changes; users clicking 'comment' on a diff view the backend refuses to model.

Related errors

• Commit {} is not in the applied workspace
• Nothing to anchor a comment to in {scope}
• Failed to communicate with LM Studio server: ${error instanc
• When using LM Studio, you must provide a valid endpoint
• No comment with id {id}

AI-assisted analysis of gitbutlerapp/gitbutler@caf1f223d3 (2026-08-20). Data as JSON: /api/errors/e4eb264e6ed922c5. Report an issue: GitHub.