Transitive Build-Depends [Was: Re: Bug#92090: failed autobuild of smpeg_0.4.2-3 (m68k): libXxf86dga (and perhaps libXxf86vm) not found, missing xlibs-dev build-depends]

[Joe Drew <hoserhead@woot.net>]

On Thu, Mar 29, 2001 at 05:13:23PM +0100, Colin Watson wrote:
> >On Thu, Mar 29, 2001 at 03:35:35PM +0200, Michael Schmitz wrote:
> >> smpeg fails to build from source on m68k - during configure, libXxf86dga
> >> isn't found. libXxf86dga is provided by xlibs-dev so please add xlibs-dev
> >> to build-depends.
> >
> >This should actually be added to libsdl1.1's build-depends, as I just
> >build-depend on that. libsdl1.1 build-depends on xlibs, while I have
> >the feeling that it should actually build-depend on xlibs-dev (just
> >an oversight, then).
> 
> Build-depends aren't applied transitively like that; only libsdl1.1's
> dependencies matter while building your package, not its
> build-dependencies.

Okay, I accept that - but why is it this way? This is counter-intuitive.
dpkg-shlibdeps has just finished being modified to detect the least number
of dependencies, and depending on apt to fulfill the chain of deps which
results. Why should Build-Depends be any different?