Function error_summary 

pub fn error_summary(error: &YsonValue) -> Option<String>

Flattens a YTsaurus error document to one line.

The outer message is a category — User job failed, Failed to run query — and the cause is at the bottom of inner_errors. Both are useful, so both are kept, and everything between them is dropped along with the attributes: a cluster error tree is mostly pids, thread names and trace ids, and the one thing a reader needs is the sentence at the bottom of it.

This is what JobInfo::error and the operation errors are built from. It is public because a caller using Client::raw_command gets the same shape of answer from any command the crate does not model, and had no way to read it — every escape-hatch caller was reinventing this, worse. Printing the tree instead is how a failed command costs an hour.

None when the document has no message at all, which is not the same as an empty one: a successful query answers {code=0;message=""}, and that summarises to Some("") rather than to nothing.

Examples

use ytsaurus_client::error_summary;
use ytsaurus_yson::{YsonFormat, from_slice};

let answer = br#"{code=1;message="Failed to run query";
    attributes={host=localhost;pid=693};
    inner_errors=[{code=1;message="Execution";
        inner_errors=[{code=1205;message="Memory limit exceeded"}]}]}"#;
let error = from_slice(answer, YsonFormat::Text).expect("the fixture parses");

assert_eq!(
    error_summary(&error).as_deref(),
    Some("Failed to run query: Memory limit exceeded"),
);