How to deal with circular BuildRequires ?

[Jonathan Underwood]

On 23/05/07, Jonathan Underwood <jonathan.underwood at gmail.com> wrote:
> Hi,
>
> Tom Tromey and I are working on packaging bbdb for Emacs (see BZ
> 226800). However, there is a circular BuildRequires. In order that the
> Emacs mailreader VM (packaged as emacs-vm) and bbdb integrate
> properly, we need to have a BuildRequires: emacs-vm-el in the
> emacs-bbdb package, and we need to have a BuildRequires: emacs-bbdb-el
> in the emacs-vm package. In other words, both packages require the
> elisp source of the other to be present at build time.
>
> Is there an established way of solving this chicken and egg situation?

I should add also that building emacs-vm without the bbdb elisp source
present will succeed, producing compiled lisp without bbdb
functionality and the source el package as well. The same is true for
emacs-bbdb. This is only an issue when wanting to enable bbdb
functionality in vm.