clenaup: don't use debug format to embed ObjectId in error message

Also fixed typo, s/a/an/.

cli/src/merge_tools/builtin.rs

@@ -21,7 +21,7 @@ pub enum BuiltinToolError {
     Record(#[from] scm_record::RecordError),
     #[error(transparent)]
     ReadFileBackend(BackendError),
-    #[error("Failed to read file {path:?} with ID {id:?}: {source}")]
+    #[error("Failed to read file {path:?} with ID {id}: {source}", id = id.hex())]
     ReadFileIo {
         path: RepoPathBuf,
         id: FileId,

lib/src/default_index/store.rs

@@ -39,7 +39,10 @@ use crate::store::Store;
 
 #[derive(Debug, Error)]
 pub enum DefaultIndexStoreError {
-    #[error("Failed to associate commit index file with a operation {op_id:?}: {source}")]
+    #[error(
+        "Failed to associate commit index file with an operation {op_id}: {source}",
+        op_id = op_id.hex()
+    )]
     AssociateIndex {
         op_id: OperationId,
         source: io::Error,