【解決】Nexus5のファクトリーイメージ書き込みでWriting 'userdata' FAILED (remote: 'Bogus size sparse and chunk header')

片付けをしていてNexus5を見つけた。廃棄しようと思い初期化しようとしたが、TWRPでカスタムROMを焼き込んでいたので、ファクトリーイメージに戻そうとしたが失敗。通常であれば、flash-all.batで一発だが、エラー。「Writing 'userdata' FAILED (remote: 'Bogus size sparse and chunk header')」

エラーメッセージ

C:\tmp>flash-all.bat
Sending 'bootloader' (3124 KB)                     OKAY [  0.318s]
Writing 'bootloader'                               OKAY [  0.506s]
Finished. Total time: 1.036s
Rebooting into bootloader                          OKAY [  0.100s]
Finished. Total time: 0.104s
Sending 'radio' (45489 KB)                         OKAY [  1.652s]
Writing 'radio'                                    OKAY [  3.108s]
Finished. Total time: 4.978s
Rebooting into bootloader                          OKAY [  0.100s]
Finished. Total time: 0.105s
--------------------------------------------
Bootloader Version...: HHZ20h
Baseband Version.....: M8974A-2.0.50.2.30
Serial Number........: 0609398222989033
--------------------------------------------
extracting android-info.txt (0 MB) to RAM...
Checking 'product'                                 OKAY [  0.093s]
Checking 'version-bootloader'                      OKAY [  0.093s]
Checking 'version-baseband'                        OKAY [  0.096s]
extracting boot.img (8 MB) to disk... took 0.020s
archive does not contain 'boot.sig'
Sending 'boot' (9156 KB)                           OKAY [  0.452s]
Writing 'boot'                                     OKAY [  0.778s]
archive does not contain 'dtbo.img'
archive does not contain 'dt.img'
extracting recovery.img (9 MB) to disk... took 0.018s
archive does not contain 'recovery.sig'
Sending 'recovery' (10014 KB)                      OKAY [  0.533s]
Writing 'recovery'                                 OKAY [  0.820s]
archive does not contain 'vbmeta.img'
archive does not contain 'vbmeta_system.img'
archive does not contain 'vendor_boot.img'
archive does not contain 'super_empty.img'
archive does not contain 'odm.img'
archive does not contain 'product.img'
extracting system.img (996 MB) to disk... took 4.090s
archive does not contain 'system.sig'
Sending 'system' (1020657 KB)                      OKAY [ 32.838s]
Writing 'system'                                   OKAY [ 69.054s]
archive does not contain 'system_ext.img'
archive does not contain 'vendor.img'
archive does not contain 'vendor_dlkm.img'
Erasing 'userdata'                                 OKAY [ 13.826s]
mke2fs 1.45.4 (23-Sep-2019)
Creating filesystem with 7137786 4k blocks and 1785856 inodes
Filesystem UUID: ccc3e534-f784-11eb-b487-8734d8c75b2f
Superblock backups stored on blocks:
        32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208,
        4096000

Allocating group tables: done
Writing inode tables: done
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

Sending 'userdata' (180 KB)                        OKAY [  0.121s]
Writing 'userdata'                                 FAILED (remote: 'Bogus size sparse and chunk header')
fastboot: error: Command failed
Press any key to exit...

いろいろ探して回避策を発見。問題が起きているuserdataは最後の方のパーティションなので、手動で書き込みをしてやる。userdataの後にcacheパーティションもあったので、そこに書き込んでおいた。

事前にファクトリーイメージの中にある.imgファイルを取り出しておく。今回は、コマンドを短くするために、platform-toolsフォルダに置いておいた。

C:\tmp>cd C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot erase userdata
******** Did you mean to fastboot format this ext4 partition?
Erasing 'userdata'                                 OKAY [ 14.409s]
Finished. Total time: 14.509s

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot flash userdata userdata.img
Sending 'userdata' (137318 KB)                     OKAY [  4.611s]
Writing 'userdata'                                 OKAY [  9.161s]
Finished. Total time: 13.988s

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot erase cache
******** Did you mean to fastboot format this ext4 partition?
Erasing 'cache'                                    OKAY [  0.605s]
Finished. Total time: 0.710s

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot flash cache cache.img
Sending 'cache' (13348 KB)                         OKAY [  0.630s]
Writing 'cache'                                    OKAY [  1.074s]
Finished. Total time: 1.915s

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot reboot
Rebooting                                          OKAY [  0.000s]
Finished. Total time: 0.003s

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot oem lock
OKAY [  0.041s]
Finished. Total time: 0.045s

C:\Users\MyPC\AppData\Local\Android\Sdk\platform-tools>fastboot reboot

こんな感じで完了。