Fail to start: AttributeError: 'module' object has no attribute 'ignore'

[Olivier Tilloy]

$ hgview
Traceback (most recent call last):
  File "/usr/bin/hgview", line 36, in <module>
    from hgviewlib.application import main
  File "/usr/lib/python2.7/dist-packages/hgviewlib/__init__.py", line 26, in <module>
    demandimport.ignore.append('roman')
AttributeError: 'module' object has no attribute 'ignore'

This upstream commit probably fixes it: https://hg.logilab.org/review/hgview/rev/523d9377bd24.

ProblemType: Bug
DistroRelease: Ubuntu 19.04
Package: hgview 1.9.0-1.1
ProcVersionSignature: Ubuntu 5.0.0-20.21-generic 5.0.8
Uname: Linux 5.0.0-20-generic x86_64
NonfreeKernelModules: zfs zunicode zavl icp zcommon znvpair
ApportVersion: 2.20.10-0ubuntu27.1
Architecture: amd64
CurrentDesktop: ubuntu:GNOME
Date: Mon Jul 15 11:12:57 2019
EcryptfsInUse: Yes
InstallationDate: Installed on 2016-07-02 (1107 days ago)
InstallationMedia: Ubuntu 16.04 LTS "Xenial Xerus" - Release amd64 (20160420.1)
PackageArchitecture: all
SourcePackage: hgview
UpgradeStatus: Upgraded to disco on 2019-03-16 (120 days ago)