Why does libgeotiff-dev depend on libtiff5-dev ?

[Alastair McKinstry <mckinstry@debian.org>]

Hi,

I'm investigating http://bugs.debian.org/cgi-bin/bugreport.cgi?bug=711789 and
wondering whats going on:

Grads fails to build due to a B-D conflict,

  grads (= 2:2.0.1-1) build-depends on one of:
  - libgeotiff-dev (= 1.3.0+dfsg-3)
  libgeotiff-dev (= 1.3.0+dfsg-3) depends on one of:
  - libtiff5-dev (= 4.0.2-6)
  libtiff4-dev (= 3.9.6-11) and libtiff5-dev (= 4.0.2-6) conflict
  libgd-dev (= 2.1.0~rc2-1) depends on one of:
  - libtiff4-dev (= 3.9.6-11)
  libgd2-xpm-dev (= 2.1.0~rc2-1) depends on one of:
  - libgd-dev (= 2.1.0~rc2-1)
  grads (= 2:2.0.1-1) build-depends on one of:
  - libgd2-xpm-dev (= 2.1.0~rc2-1)
  - libgd-dev (= 2.1.0~rc2-1)


I'm unfamiliar with the history of libtiff4 / tiff5, but libgd-dev depends on libtiff-dev ; 
can anyone answer:
(1) why does libgeotiff-dev depend on libtiff5-dev?
(2) why libtiff5-dev not provide the virtual libtiff-dev?

Best regards
Alastair


-- 
Alastair McKinstry  , <alastair@sceal.ie> , <mckinstry@debian.org>  http://diaspora.sceal.ie/u/amckinstry
Anyone who believes exponential growth can go on forever in a finite world
is either a madman or an economist - Kenneth Boulter, Economist.