Method onError

packages/core/src/tools/grep.ts:419–422

(err: Error)

              }
            };
            const onError = (err: Error) => {
              cleanup();
              reject(new Error(`Failed to start system grep: ${err.message}`));
            };
            const onClose = (code: number | null) => {
              const stdoutData = Buffer.concat(stdoutChunks).toString('utf8');
              const stderrData = Buffer.concat(stderrChunks)