[Pkg-emacsen-addons] Bug#869509: dh-elpa: please support tuning which emacs flavors to skip

[Aaron M. Ucko]

Package: dh-elpa
Version: 1.8
Severity: normal

dh-elpa supplies emacsen-common install and remove scripts that
hardcode the list of emacs flavors to skip as obsolete (GNU Emacs 23
and below) or simply unsupported (XEmacs).  This one-size-fits-all
approach has two drawbacks:
 - It does not fully accommodate packages that have retained
   compatibility with some or all of the skipped flavors.
 - It forces packages that are compatible only with Emacs 25 to
   declare outright conflicts with Emacs 24, rather than simply
   skipping byte-compilation for it.

I find the latter particularly concerning, because the former is
easier to work around.  (Yes, I do prefer Emacs 25 myself, but I keep
a full range of Emacs flavors installed for compatibility testing.)

Please give packages an opportunity to tune the set of flavors to
skip, and then use this feature to retire elpa-apiwrap's,
elpa-ghub(+)'s, and elpa-magithub's conflicts with Emacs 24.

Thanks!

-- System Information:
Debian Release: buster/sid
  APT prefers testing
  APT policy: (500, 'testing'), (500, 'stable'), (300, 'unstable')
Architecture: amd64 (x86_64)
Foreign Architectures: i386, x32

Kernel: Linux 4.11.0-2-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 dh-elpa depends on:
ii  debhelper               10.2.5
ii  dh-make-perl            0.95
ii  emacs24                 24.5+1-11
ii  emacs25                 25.2+1-1
ii  libarray-utils-perl     0.5-1
ii  libconfig-tiny-perl     2.23-1
ii  libdebian-source-perl   0.95
ii  libdpkg-perl            1.18.24
ii  libfile-find-rule-perl  0.34-1
ii  libtext-glob-perl       0.10-1
ii  perl                    5.24.1-7

dh-elpa recommends no packages.

dh-elpa suggests no packages.

-- no debconf information