これの投げてる例外らしいが分からん
/**
* Look up the last modification time of the JSON dump.
*
* @param {String} bucket
* @param {String} collection
* @return {int} The last modification time of the dump. -1 if non-existent.
*/
async getLocalDumpLastModified(bucket, collection) {
if (!this._dumpStats) {
if (!this._dumpStatsInitPromise) {
this._dumpStatsInitPromise = (async () => {
try {
let res = await fetch(
"resource://app/defaults/settings/last_modified.json"
);
this._dumpStats = await res.json();
} catch (e) {
log.warn(`Failed to load last_modified.json: ${e}`);
this._dumpStats = {};
}
delete this._dumpStatsInitPromise;
})();
}
await this._dumpStatsInitPromise;
}