Bug#163637: apt-cache: information on Build-Depends

[Matt Taggart <taggart@debian.org>]

I agree with the submitters of #163637 and #190891 that it would be nice to 
have a way to determine the list of Source packages that build-depend on a 
given package. The wishlist bug #301041 points to a tool that figures this out 
using libapt-pkg-perl and then also graphs the result using dotty.

I also asked on #debian-devel and Clint mentioned his solution for the 
problems,

<Clint> grep-available -F Build-Depends -s Package libgtk /var/lib/apt/\
  lists/ftp.us.debian.org_debian_dists_unstable_main_source_Sources

While those two solutions will work, I still think the ideal solution would be 
something like

apt-cache rbuild-dep foo

and as long as you were at it you could provide one for the forward depends 
too,

apt-cache build-dep foo

which would just be the build-deps part of showsrc, analogous to how 
depends/rdepends show info from showpkg.

-- 
Matt Taggart
taggart@debian.org