leverage snafu for better scanning error messages

src/scanner.rs

@@ -2,7 +2,7 @@
 
 use std::{fs::File, io, path::PathBuf};
 
-use snafu::{ResultExt, Snafu};
+use snafu::{Report, ResultExt, Snafu};
 use tracing::{error, info};
 
 use crate::{
@@ -27,11 +27,13 @@ pub async fn scan(
         match book_result {
             Ok(book) => {
                 if let Err(e) = process_book(&book, db, tokenizer, text_encoder, chunk_size).await {
-                    error!("Failed to process book {}: {e}", book.id);
+                    let error = Report::from_error(e);
+                    error!("Failed to process book {}: {}", book.id, error.to_string());
                 }
             }
             Err(e) => {
-                error!("error fetching calibre book: {e}");
+                let error = Report::from_error(e);
+                error!("error fetching calibre book: {}", error.to_string());
             }
         }
     }