Bug#914256: lintian: conflict between no-template-description and untranslatable-debconf-templates

[Vincent McIntyre <vincent.mcintyre@csiro.au>]

Package: lintian
Version: 2.5.50.4
Severity: normal

   * What led up to the situation?

(The issue is independent of the 'hello' package, I just used it to make
 reproduction easier.)

$ apt-get source hello

$ cd hello-2.10

$ cat > debian/templates
Template: hello/all-languages
Type: boolean
Default: false
Description: Use all available languages?
 This program can speak in many languages.

$ cat >debian/config
#!/bin/sh -e
# This may ask for config info but should not change anything
# Postinst should change things.

# Source debconf library.
. /usr/share/debconf/confmodule

db_title "hello" || true


$ debuild -us -uc
...
Now running lintian...
...
E: hello source: untranslatable-debconf-templates templates: 4
...

So far, so good.
But if I do what seems to be the recommended thing I get told off again:

$ sed -i -e 's/^Desc/_Desc/' debian/templates
$ debuild -us -uc
...
Now running lintian...
...
E: hello: no-template-description hello/all-languages
E: hello: unknown-field-in-templates hello/all-languages _description

I did try putting both a Description: and _Description: field in but that
did not work either.

This seems like a bug, but if I'm missing some templating magic spell
I would be happy to help document it better.

I've already consulted the sources below:
 - https://manpages.debian.org/stretch/debconf-doc/debconf-devel.7.en.html
 - https://www.debian.org/doc/debian-policy/ch-binary.html#prompting-in-maintainer-scripts
 - https://www.debian.org/doc/packaging-manuals/debconf_specification.html

I also had a look at the git repository and could not see recent
work related to either of the tags involved here.

Kind regards
Vince

-- System Information:
Debian Release: 9.6
  APT prefers stable
  APT policy: (990, 'stable'), (500, 'stable-debug')
Architecture: amd64 (x86_64)

Kernel: Linux 4.9.0-8-amd64 (SMP w/8 CPU cores)
Locale: LANG=en_AU.UTF-8, LC_CTYPE=en_AU.UTF-8 (charmap=UTF-8), LANGUAGE=en_AU:en (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages lintian depends on:
ii  binutils                          2.28-5
ii  bzip2                             1.0.6-8.1
ii  diffstat                          1.61-1+b1
ii  file                              1:5.30-1+deb9u2
ii  gettext                           0.19.8.1-2
ii  intltool-debian                   0.35.0+20060710.4
ii  libapt-pkg-perl                   0.1.32
ii  libarchive-zip-perl               1.59-1+deb9u1
ii  libclass-accessor-perl            0.34-1
ii  libclone-perl                     0.38-2+b1
ii  libdpkg-perl                      1.18.25
ii  libemail-valid-perl               1.202-1
ii  libfile-basedir-perl              0.07-1
ii  libipc-run-perl                   0.94-1+deb9u1
ii  liblist-moreutils-perl            0.416-1+b1
ii  libparse-debianchangelog-perl     1.2.0-12
ii  libperl5.24 [libdigest-sha-perl]  5.24.1-3+deb9u4
ii  libtext-levenshtein-perl          0.13-1
ii  libtimedate-perl                  2.3000-2
ii  liburi-perl                       1.71-1
ii  libyaml-libyaml-perl              0.63-2
ii  man-db                            2.7.6.1-2
ii  patchutils                        0.3.4-2
ii  perl                              5.24.1-3+deb9u4
ii  t1utils                           1.39-2
ii  xz-utils                          5.2.2-1.2+b1

Versions of packages lintian recommends:
ii  dpkg                                 1.18.25
pn  libperlio-gzip-perl                  <none>
ii  perl                                 5.24.1-3+deb9u4
ii  perl-modules-5.24 [libautodie-perl]  5.24.1-3+deb9u4

Versions of packages lintian suggests:
pn  binutils-multiarch     <none>
ii  dpkg-dev               1.18.25
ii  libhtml-parser-perl    3.72-3
ii  libtext-template-perl  1.46-1

-- no debconf information