Bug#885437: debsnap: fails when an old version uses a now-invalid version number

[Marvin Renich]

Package: devscripts
Version: 2.17.11
Severity: normal

If a package has in the past used a version number that is no longer
valid, debsnap cannot download any version of that package.

$ debsnap --binary -d . -a amd64 libnspr4 2:4.16-1
debsnap: error: M18-3 is not a valid version

According to snapshot.debian.org, in 2009 libnspr4 was built from source
package mozilla version M18-3.  This is no longer a valid Debian version
number, but was then(?).  debsnap cannot download a recent version of
this package because the available-version information from snapshot.d.o
contains a version number that debsnap doesn't know how to handle.

...Marvin

-- Package-specific info:

--- /etc/devscripts.conf ---

--- ~/.devscripts ---
Not present

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'stable-updates'), (500, 'stable'), (200, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.13.0-1-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_US.UTF-8, LC_CTYPE=en_US.UTF-8 (charmap=UTF-8), LANGUAGE=en_US.UTF-8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: sysvinit (via /sbin/init)

Versions of packages devscripts depends on:
ii  dpkg-dev              1.19.0.4
ii  libc6                 2.25-3
ii  libfile-homedir-perl  1.002-1
ii  perl                  5.26.1-3
ii  python3               3.6.4~rc1-2
ii  sensible-utils        0.0.11

Versions of packages devscripts recommends:
ii  apt                         1.6~alpha5
ii  at                          3.1.20-3.1
ii  curl                        7.57.0-1
ii  dctrl-tools                 2.24-2+b1
ii  debian-keyring              2017.11.24
ii  dput-ng [dput]              1.15
pn  equivs                      <none>
ii  fakeroot                    1.22-2
ii  file                        1:5.32-1
ii  gnupg                       2.2.3-1
ii  libdistro-info-perl         0.17
ii  libdpkg-perl                1.19.0.4
ii  libencode-locale-perl       1.05-1
ii  libgit-wrapper-perl         0.047-1
ii  liblist-compare-perl        0.53-1
ii  liblwp-protocol-https-perl  6.07-2
ii  libsoap-lite-perl           1.23-1
ii  liburi-perl                 1.72-2
ii  libwww-perl                 6.29-1
ii  licensecheck                3.0.31-2
ii  lintian                     2.5.65
ii  man-db                      2.7.6.1-4
ii  patch                       2.7.5-1+b2
ii  patchutils                  0.3.4-2
ii  python3-apt                 1.4.0~beta3+b1
ii  python3-debian              0.1.31
ii  python3-magic               1:5.32-1
ii  python3-requests            2.18.1-1
pn  python3-unidiff             <none>
ii  python3-xdg                 0.25-4
ii  strace                      4.19-1
ii  unzip                       6.0-21
ii  wdiff                       1.2.2-2
ii  wget                        1.19.2-1
ii  xz-utils                    5.2.2-1.3

Versions of packages devscripts suggests:
pn  adequate                     <none>
pn  autopkgtest                  <none>
pn  bls-standalone               <none>
ii  bsd-mailx [mailx]            8.1.2-0.20160123cvs-4
ii  build-essential              12.4
pn  check-all-the-things         <none>
pn  cvs-buildpackage             <none>
pn  devscripts-el                <none>
pn  diffoscope                   <none>
pn  disorderfs                   <none>
pn  dose-extra                   <none>
pn  duck                         <none>
pn  faketime                     <none>
ii  gnuplot                      5.2.2+dfsg1-2
ii  gnuplot-qt [gnuplot]         5.2.2+dfsg1-2
ii  gpgv                         2.2.3-1
pn  how-can-i-help               <none>
ii  libauthen-sasl-perl          2.1600-1
ii  libfile-desktopentry-perl    0.22-1
pn  libnet-smtps-perl            <none>
pn  libterm-size-perl            <none>
ii  libtimedate-perl             2.3000-2
pn  libyaml-syck-perl            <none>
ii  mailutils [mailx]            1:3.4-1
pn  mozilla-devscripts           <none>
ii  mutt                         1.9.2-1
ii  openssh-client [ssh-client]  1:7.6p1-2
pn  piuparts                     <none>
ii  quilt                        0.63-8.1
pn  ratt                         <none>
pn  reprotest                    <none>
pn  svn-buildpackage             <none>
ii  w3m                          0.5.3-34.1

-- no debconf information