Windows Subsystem for Linux upgrade failed mercurial-common 2.8.2 to 3.7.3

When upgrading Ubuntu 14.04 to 16.04

/usr/lib/python2.7/dist-packages/hgext/win32mbcs.py

it seems no such file...

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mercurial-common 2.8.2-1ubuntu1.3
ProcVersionSignature: Microsoft 4.4.0-43-Microsoft 4.4.35
Uname: Linux 4.4.0-43-Microsoft x86_64
ApportVersion: 2.20.1-0ubuntu2.13
Architecture: amd64
Date: Tue Nov 21 12:30:06 2017
Dmesg: [ 0.000000]
ErrorMessage: (今インストールしようとしている) `./usr/lib/python2.7/dist-packages/hgext/win32mbcs.py' の状態を取得できません: 入力/出力エラーです
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.2
 apt 1.2.24
SourcePackage: mercurial
Title: package mercurial-common 2.8.2-1ubuntu1.3 failed to install/upgrade: (今インストールしようとしている) `./usr/lib/python2.7/dist-packages/hgext/win32mbcs.py' の状態を取得できません: 入力/出力エラーです
UpgradeStatus: Upgraded to xenial on 2017-11-21 (0 days ago)