Rasperry Pi（Raspian）でノードアプリケーションを実行していますが、このエラーが2回発生するのを見ました。突然、次の内容で満たされたエラーログが表示されます。
You have triggered an unhandledRejection, you may have forgotten to catch a Promise rejection:
Error: ER_ACCESS_DENIED_ERROR: Access denied for user 'hub_user'@'loS' (using password: YES)
at Handshake.Sequence._packetToError (/opt/data/Hub/node_modules/mysql/lib/protocol/sequences/Sequence.js:$
at Handshake.ErrorPacket (/opt/data/Hub/node_modules/mysql/lib/protocol/sequences/Handshake.js:103:18)
at Protocol._parsePacket (/opt/data/Hub/node_modules/mysql/lib/protocol/Protocol.js:280:23)
at Parser.write (/opt/data/Hub/node_modules/mysql/lib/protocol/Parser.js:74:12)
at Protocol.write (/opt/data/Hub/node_modules/mysql/lib/protocol/Protocol.js:39:16)
at Socket.<anonymous> (/opt/data/Hub/node_modules/mysql/lib/Connection.js:109:28)
at emitOne (events.js:77:13)
at Socket.emit (events.js:169:7)
at readableAddChunk (_stream_readable.js:153:18)
at Socket.Readable.push (_stream_readable.js:111:10)
at TCP.onread (net.js:537:20)
--------------------
at Protocol._enqueue (/opt/data/Hub/node_modules/mysql/lib/protocol/Protocol.js:141:48)
at Protocol.handshake (/opt/data/Hub/node_modules/mysql/lib/protocol/Protocol.js:52:41)
at Connection.connect (/opt/data/Hub/node_modules/mysql/lib/Connection.js:136:18)
at /opt/data/Hub/node_modules/knex/lib/dialects/mysql/index.js:106:18
at Promise._execute (/opt/data/Hub/node_modules/knex/node_modules/bluebird/js/release/debuggability.js:300$
at Promise._resolveFromExecutor (/opt/data/Hub/node_modules/knex/node_modules/bluebird/js/release/promise.$
at new Promise (/opt/data/Hub/node_modules/knex/node_modules/bluebird/js/release/promise.js:77:14)
at Client_MySQL.acquireRawConnection (/opt/data/Hub/node_modules/knex/lib/dialects/mysql/index.js:104:12)
at Object.create (/opt/data/Hub/node_modules/knex/lib/client.js:231:16)
at Pool._createResource (/opt/data/Hub/node_modules/knex/node_modules/generic-pool/lib/generic-pool.js:326$
at Pool.dispense [as _dispense] (/opt/data/Hub/node_modules/knex/node_modules/generic-pool/lib/generic-poo$
at Pool.acquire (/opt/data/Hub/node_modules/knex/node_modules/generic-pool/lib/generic-pool.js:392:8)
at /opt/data/Hub/node_modules/knex/lib/client.js:281:19
at Promise._execute (/opt/data/Hub/node_modules/knex/node_modules/bluebird/js/release/debuggability.js:300$
at Promise._resolveFromExecutor (/opt/data/Hub/node_modules/knex/node_modules/bluebird/js/release/promise.$
at new Promise (/opt/data/Hub/node_modules/knex/node_modules/bluebird/js/release/promise.js:77:14)
SSHを介してデバイスに接続するとき（この状態に入るとき）、次のように入力します。
mysql -uhub_user -p
"hub_user"@"loS"で接続を試みます。 "hub_user"@"localhost"を指定すると、localhostの後に"loS"が追加されます。
これがどこから出てくるのか知っている人はいますか？