繼一個季度前申請 49 元換電池無果厚，前幾天小米售後竟然電話通知浅羽說：電池到貨了，可以換電池了。浅羽確認更換電池價格依然爲 49 元後，因爲小米售後創建的工單顯示是「自行到店維修」，因此詢問可否寄修。對此小米售後的回覆是肯定的，但要求解除鎖定螢幕密碼並自行備份好重要資料。

浅羽的手機上沒有什麼重要資料，但照片、聊天之類的私隱內容不帶密碼地交到陌生人手上終歸是不放心。所以當然，先用 Titanium Backup 備份一遍所有程式的資料，再用 TWRP 備份 Data 分割區，最後把照片和備份資料全都移動到電腦上，寄一臺空手機維修。進入 TWRP 後顯示 Data 分割區備份約需要 11G，但開始備份後很快就中止了，生成的備份檔只有 500M 不到，並且還有錯誤提醒：

createTarFork() process ended with ERROR: 255

再試兩次，還是如此。上網路搜尋，發現原來不止浅羽有遇到這個問題；有人已經把問題回報到官方：

WHAT IS THE EXPECTED RESULT?

TWRP backs up data.

WHAT HAPPENS INSTEAD?

TWRP fails to backup. The error message is [createTarFork() process ended with ERROR: 255].

TeamWin/Team-Win-Recovery-Project#1373: createTarFork() process ended with ERROR: 255 when trying to back up data with multiple users

下面的評論有提到原因，並且給了一個臨時解決方案：

I experience the same problem with my device (Chiron) using both the latest and previous TWRP versions.
When I decrypt the device in TWRP there are still some encrypted folders:

– /data/user/10

– /data/misc_ce/10

– /data/system_ce/10

These folders belong to a second user profile (in my case created by the app cloner ‘Island’)

DrFunx – issuecomment-457226514

Besides deleting the second user with pm remove-user [user_id], is there any other workaround for this issue? This affects any phone/ROM that uses android’s FBE when creating a new profile (pretty much all of them), and has been ongoing for quite some time (almost an year that I remember).

Is it too hard to just skip all the other profile’s directories (or everything that’s file-based encrypted for that matter) when using TWRP to backup and restore?

esauvisky – issuecomment-461204954

Well, if you’re fine with the data being removed for your dual apps, please try flashing this before trying a backup and/or a restore: RMDAD_v0.0.1.zip

That will remove any 999/10 folders, flashable in TWRP. Please report back.

pannal – issuecomment-568148330

然而說到底，雖然明白了原因、也有了臨時方案，但終歸不是徹底的解決方案，因爲這樣會丟失部分資料。浅羽目前有使用「應用雙開」功能，第二個應用的資料是無法備份的（並且還會被刪除）。那麼爲什麼 TWRP 對此不做一些改進呢？

Time. Time for the TWRP devs to review the relevant patch on Gerrit. Be patient.

CaptainThrowback – issuecomment-519184663

Fix for this has been merged and will be included in the next official TWRP release.

CaptainThrowback – issuecomment-632764147

而且這位貌似還是猩猩玩家，當有人詢問包含修正的新版本什麼時候釋出時，這位不假思索地回答道：

Soon™

CaptainThrowback – issuecomment-635588958