Bug#814049: /usr/bin/uscan: uscan gives invalid example in manpage for github tags

[Ximin Luo]

Package: devscripts
Version: 2.15.10
Severity: normal
File: /usr/bin/uscan

Dear Maintainer,

In uscan's manpage, it gives this example for github tags:

         version=4
         opts="filenamemangle="s%(?:.*?)?v?(\d[\d.]*)\.tar\.gz%<project>-$1.tar.gz%" \
             https://github.com/<user>/<project>/tags \
             (?:.*?/)?v?(\d[\d.]*)\.tar\.gz debian uupdate

However when I actually use it:

~~~~
version=4
opts="filenamemangle="s%(?:.*?)?v?(\d[\d.]*)\.tar\.gz%baka-mplayer-$1.tar.gz%" \
 https://github.com/u8sand/Baka-MPlayer/tags \
 (?:.*?/)?v?(\d[\d.]*)\.tar\.gz debian uupdate
~~~~

uscan tells me:

uscan warn: In debian/watch, potentially unsafe or malformed filenamemangle pattern:
  '"s%(?:.*?)?v?(\d[\d.]*)\.tar\.gz%baka-mplayer-$1.tar.gz%' found. Skipping watchline
  https://github.com/u8sand/Baka-MPlayer/tags (?:.*?/)?v?(\d[\d.]*)\.tar\.gz debian uupdate
1

This is bad for two reasons:

- many people will copy this out of the manpage
- it gives me no indication on why it's unsafe nor how to fix my watch file

Please fix?

Thanks,
X

-- Package-specific info:

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

--- ~/.devscripts ---
export DEBSIGN_PROGRAM="gpg2"

-- System Information:
Debian Release: stretch/sid
  APT prefers testing
  APT policy: (990, 'testing'), (500, 'stable'), (300, 'unstable'), (200, 'experimental')
Architecture: amd64 (x86_64)
Foreign Architectures: i386

Kernel: Linux 4.3.0-1-amd64 (SMP w/4 CPU cores)
Locale: LANG=en_GB.utf8, LC_CTYPE=en_GB.utf8 (charmap=UTF-8)
Shell: /bin/sh linked to /bin/dash
Init: systemd (via /run/systemd/system)

Versions of packages devscripts depends on:
ii  dpkg-dev     1.18.4
ii  libc6        2.21-7
ii  perl         5.20.2-6
pn  python3:any  <none>

Versions of packages devscripts recommends:
ii  apt                         1.2.1
ii  at                          3.1.18-2
ii  curl                        7.47.0-1
ii  dctrl-tools                 2.24-2
ii  debian-keyring              2016.01.20
ii  dput                        0.9.6.4
ii  equivs                      2.0.9+nmu1
ii  fakeroot                    1.20.2-1
ii  file                        1:5.25-2
ii  gnupg                       1.4.20-1
ii  gnupg2                      2.1.11-2
ii  libdistro-info-perl         0.14
ii  libencode-locale-perl       1.05-1
ii  libjson-perl                2.90-1
ii  liblwp-protocol-https-perl  6.06-2
ii  libsoap-lite-perl           1.19-1
ii  liburi-perl                 1.71-1
ii  libwww-perl                 6.15-1
ii  lintian                     2.5.40.2
ii  man-db                      2.7.5-1
ii  patch                       2.7.5-1
ii  patchutils                  0.3.4-1
ii  python3-debian              0.1.27
ii  python3-magic               1:5.25-2
ii  sensible-utils              0.0.9
ii  strace                      4.10-3
ii  unzip                       6.0-20
ii  wdiff                       1.2.2-1+b1
ii  wget                        1.17.1-1+b1
ii  xz-utils                    5.1.1alpha+20120614-2.1

Versions of packages devscripts suggests:
ii  bsd-mailx [mailx]            8.1.2-0.20150408cvs-1
ii  build-essential              11.7
pn  cvs-buildpackage             <none>
pn  debbindiff                   <none>
pn  devscripts-el                <none>
ii  gnuplot                      4.6.6-3
ii  gpgv                         1.4.20-1
ii  libauthen-sasl-perl          2.1600-1
ii  libfile-desktopentry-perl    0.22-1
ii  libnet-smtp-ssl-perl         1.03-1
pn  libterm-size-perl            <none>
ii  libtimedate-perl             2.3000-2
ii  libyaml-syck-perl            1.29-1
ii  mozilla-devscripts           0.44
ii  mutt                         1.5.24-1+b1
ii  openssh-client [ssh-client]  1:7.1p2-2
ii  s-nail [mailx]               14.8.6-1
pn  svn-buildpackage             <none>
ii  w3m                          0.5.3-26

-- no debconf information