package mercurial-common 3.7.3-1ubuntu1 failed to install/upgrade: subprocess installed pre-removal script returned error exit status 127

[Abhimanu]

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Setting up mercurial-common (3.7.3-1ubuntu1) ...
/var/lib/dpkg/info/mercurial-common.postinst: 6: /var/lib/dpkg/info/mercurial-common.postinst: pycompile: not found
dpkg: error processing package mercurial-common (--configure):
 subprocess installed post-installation script returned error exit status 127
dpkg: error processing package python-libxml2 (--configure):
 package is in a very bad inconsistent state; you should
 reinstall it before attempting configuration
Errors were encountered while processing:
 mercurial-common
 python-libxml2
E: Sub-process /usr/bin/dpkg returned an error code (1)

ProblemType: Package
DistroRelease: Ubuntu 16.04
Package: mercurial-common 3.7.3-1ubuntu1
ProcVersionSignature: Ubuntu 4.10.0-42.46~16.04.1-generic 4.10.17
Uname: Linux 4.10.0-42-generic x86_64
ApportVersion: 2.20.1-0ubuntu2.14
Architecture: amd64
Date: Tue Dec 19 21:49:30 2017
DuplicateSignature:
 package:mercurial-common:3.7.3-1ubuntu1
 Removing mercurial-common (3.7.3-1ubuntu1) ...
 /var/lib/dpkg/info/mercurial-common.prerm: 9: /var/lib/dpkg/info/mercurial-common.prerm: pyclean: not found
 dpkg: error processing package mercurial-common (--remove):
  subprocess installed pre-removal script returned error exit status 127
ErrorMessage: subprocess installed pre-removal script returned error exit status 127
InstallationDate: Installed on 2017-12-14 (4 days ago)
InstallationMedia: Ubuntu 16.04.3 LTS "Xenial Xerus" - Release amd64 (20170801)
PackageArchitecture: all
RelatedPackageVersions:
 dpkg 1.18.4ubuntu1.3
 apt 1.2.24
SourcePackage: mercurial
Title: package mercurial-common 3.7.3-1ubuntu1 failed to install/upgrade: subprocess installed pre-removal script returned error exit status 127
UpgradeStatus: No upgrade log present (probably fresh install)