Hmbown/CodeWhale · error · anyhow::Error

failed to parse original config for comment merge; file cont

Error message

failed to parse original config for comment merge; file contents were omitted

What it means

merge_and_preserve_comments re-parses the original file text with toml_edit so user comments, whitespace, and trailing notes survive a config rewrite. This error says the original_raw argument is not valid TOML; the merge is refused before any output is produced.

Source

Thrown at crates/config/src/lib.rs:5330

            }
        } else if let Some(nested) = item.as_table_like_mut() {
            remove_plaintext_api_keys_recursive(nested);
        }
    }
}

/// Merge comments and formatting from an original TOML file into a
/// freshly serialized document so user annotations (comments, whitespace,
/// disabled keys) survive config rewrites.
///
/// `original_raw` is the raw text of the file before the change; the
/// function parses it internally with [`toml_edit`] so callers stay free
/// of that dependency.
pub fn merge_and_preserve_comments(serialized: &str, original_raw: &str) -> Result<String> {
    let original = original_raw
        .parse::<toml_edit::DocumentMut>()
        .map_err(|_| {
            anyhow::anyhow!(
                "failed to parse original config for comment merge; file contents were omitted"
            )
        })?;

    let mut new_doc = serialized.parse::<toml_edit::DocumentMut>().map_err(|_| {
        anyhow::anyhow!(
            "failed to parse serialized config for comment merge; file contents were omitted"
        )
    })?;

    // Reuse the original document’s trailing text (file-footer comments /
    // disabled keys) so they survive the rewrite.
    new_doc.set_trailing(original.trailing().clone());

    // Copy the top-level table's decor (document-header comments, whitespace
    // before the first key) which `toml_edit` stores on the root `Table` itself.
    *new_doc.as_table_mut().decor_mut() = original.as_table().decor().clone();

View on GitHub (pinned to 8880682c63)

Solutions

1. Validate and repair the original file before the rewrite; this function intentionally refuses to guess
2. Remove duplicate keys; toml_edit is strict about them
3. If the original is unrecoverable, write the serialized document without comment merging and accept losing comments

Example fix

// before: merging against broken original text
let merged = merge_and_preserve_comments(&serialized, &broken_raw)?;

// after: only merge when the original still parses
let merged = match broken_raw.parse::<toml_edit::DocumentMut>() {
    Ok(_) => merge_and_preserve_comments(&serialized, &broken_raw)?,
    Err(_) => serialized.clone(), // rewrite without preserved comments
};

// Only merge comments when the original text still parses:
let can_merge = original_raw.parse::<toml_edit::DocumentMut>().is_ok();

Wrap the merge call and on Err fall back to writing the serialized document without comment preservation. A failed merge must not block the save: prefer losing comments over losing the config change.

When it happens

Trigger: Calling the public merge_and_preserve_comments with original_raw that fails toml_edit parsing (bad syntax or duplicate keys), typically because the on-disk file was already broken when a save was attempted or a test fed hand-written original text.

Common situations: A save path that captured original_raw at startup while another process corrupted the file before the write; embedders/tests constructing the original string by hand with a typo.

Understand the failure class

• Parsing and encoding errors: unexpected token, malformed input — why parsers reject input and how to find the real culprit.

Related errors

• failed to parse config at {}; file contents were omitted
• failed to parse config at {}; file contents were omitted
• failed to parse config TOML while removing plaintext API key
• failed to parse serialized config for comment merge; file co
• failed to parse permissions at {}; file contents were omitte

AI-assisted analysis of Hmbown/CodeWhale@8880682c63 (2026-08-16). Data as JSON: /api/errors/b95ec9222b74a4f4. Report an issue: GitHub.