Bug#873157: diffoscope: Support the new fork of python-progressbar

[Santiago Torres-Arias]

Package: diffoscope
Version: 85
Severity: wishlist
Tags: upstream

Dear Maintainer,

While trying to install/use diffoscope from pip (or the Arch Linux
package), I realized that the --progress flag triggers a crash. The
reason as to why this happens is that there are two forks of the
python-progressbar package available, whith slightly different api's.

The one being used by Debian[1] seems to be an abandoned version
(without any updates in two years), whereas there exists a more
actively-developed alternative[2] (possible a takeover). This issue has
also been brought up to the maintainers of python-progressbar, who are
evaluating this upstream change[3]. An arch user suggested a fairly
minimal patch to fix it[4], and there is an more-elaborate descrption of
the API change on the comments of this bug report[5].

It'd be nice if diffoscope was made aware of these versions and possibly
choose the right one depending on which one is available.

Thanks!
-Santiago.

[1] https://github.com/niltonvolpato/python-progressbar
[2] https://github.com/WoLpH/python-progressbar
[3] https://bugs.debian.org/cgi-bin/bugreport.cgi?bug=839149
[4] http://codepad.org/oIr6JudF
[5] https://bugs.archlinux.org/task/53505

-- System Information:
Debian Release: 9.1
  APT prefers stable
  APT policy: (500, 'stable')
Architecture: amd64 (x86_64)

Kernel: Linux 4.12.7-coreos (SMP w/8 CPU cores) 
Locale: LANG=C, LC_CTYPE=C (charmap=ANSI_X3.4-1968), LANGUAGE=C (charmap=ANSI_X3.4-1968)
Shell: /bin/sh linked to /usr/bin/dash
Init: unable to detect

Versions of packages diffoscope depends on:
ii  python3                3.5.3-1
pn  python3-libarchive-c   <none>
pn  python3-magic          <none>
ii  python3-pkg-resources  33.1.1-1

Versions of packages diffoscope recommends:
pn  acl                                            <none>
pn  apktool                                        <none>
pn  binutils-multiarch                             <none>
ii  bzip2                                          1.0.6-8.1
pn  caca-utils                                     <none>
pn  colord                                         <none>
pn  default-jdk-headless | default-jdk | java-sdk  <none>
pn  enjarify                                       <none>
pn  fontforge-extras                               <none>
pn  fp-utils                                       <none>
pn  genisoimage                                    <none>
pn  gettext                                        <none>
pn  ghc                                            <none>
pn  ghostscript                                    <none>
pn  gnupg                                          <none>
pn  imagemagick                                    <none>
pn  jsbeautifier                                   <none>
pn  llvm                                           <none>
pn  mono-utils                                     <none>
pn  openssh-client                                 <none>
pn  pdftk                                          <none>
pn  poppler-utils                                  <none>
pn  python3-argcomplete                            <none>
ii  python3-debian                                 0.1.30
pn  python3-guestfs                                <none>
pn  python3-progressbar                            <none>
pn  python3-rpm                                    <none>
pn  python3-tlsh                                   <none>
pn  rpm2cpio                                       <none>
pn  sng                                            <none>
pn  sqlite3                                        <none>
pn  squashfs-tools                                 <none>
pn  unzip                                          <none>
pn  xxd | vim-common                               <none>
ii  xz-utils                                       5.2.2-1.2+b1

Versions of packages diffoscope suggests:
pn  libjs-jquery  <none>