Bug#920763: lintian: orig-tarball-missing-upstream-signature interacts poorly with mode=git,pgpmode=gittag

[Daniel Kahn Gillmor <dkg@fifthhorseman.net>]

Package: lintian
Version: 2.5.124
Severity: normal
Control: affects -1 src:wireguard

In wireguard's debian/watch, we have:

  opts=mode=git,pgpmode=gittag

So we don't use an "upstream tarball" other than the git repo, which
has a signed tag in it.  But lintian complains:

   W: orig-tarball-missing-upstream-signature

It would be nice if lintian could identify that this is using signed
git tags, and avoid the warning -- or, if it is using signed git tags,
at least produce a suggestion of what to do with them.

   --dkg


-- System Information:
Debian Release: buster/sid
  APT prefers testing-debug
  APT policy: (500, 'testing-debug'), (500, 'testing'), (200, 'unstable-debug'), (200, 'unstable'), (1, 'experimental-debug'), (1, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.19.0-1-amd64 (SMP w/4 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: systemd (via /run/systemd/system)

Versions of packages lintian depends on:
ii  binutils                       2.31.1-11
ii  bzip2                          1.0.6-9
ii  diffstat                       1.62-1
ii  dpkg                           1.19.2
ii  dpkg-dev                       1.19.2
ii  file                           1:5.35-2
ii  gettext                        0.19.8.1-9
ii  gpg                            2.2.12-1
ii  intltool-debian                0.35.0+20060710.5
ii  libapt-pkg-perl                0.1.34+b1
ii  libarchive-zip-perl            1.64-1
ii  libcgi-pm-perl                 4.40-1
ii  libclass-accessor-perl         0.51-1
ii  libclone-perl                  0.41-1+b1
pn  libdigest-sha-perl             <none>
ii  libdpkg-perl                   1.19.2
ii  libemail-valid-perl            1.202-1
ii  libfile-basedir-perl           0.08-1
ii  libio-async-perl               0.72-1
ii  libipc-run-perl                20180523.0-1
ii  liblist-moreutils-perl         0.416-1+b4
ii  libparse-debianchangelog-perl  1.2.0-13
ii  libtext-levenshtein-perl       0.13-1
ii  libtimedate-perl               2.3000-2
ii  liburi-perl                    1.76-1
ii  libxml-simple-perl             2.25-1
ii  libyaml-libyaml-perl           0.76+repack-1
ii  man-db                         2.8.5-1
ii  patchutils                     0.3.4-2
ii  perl                           5.28.1-3
ii  t1utils                        1.41-3
ii  xz-utils                       5.2.2-1.3

Versions of packages lintian recommends:
pn  libperlio-gzip-perl  <none>

Versions of packages lintian suggests:
pn  binutils-multiarch     <none>
ii  libhtml-parser-perl    3.72-3+b3
ii  libtext-template-perl  1.54-1

-- no debconf information