[Rpm-maint] [Patch 3/19] Enable PREREQ

[Peter Bowen]

PreReq is a hint that can be used to get better package ordering when
you are left with little else.  For example:

Package A requires B and C
Package B requires A
Package C requires nothing new
None are installed on the system
User request: Install A, B, and C.

with just this information, we know they all have to be installed at the
end of the transaction. We know that C will be the first package
installed, and that all will exist at the end of the transaction.  How
do you decide if you install in the order C, A, B or C, B, A?

Each require line can have hints associated to help solve this issue.
If you are really lucky, you will have per-scriptlet hints to tell you
if the dependency is needed for %post, but a second best choice is the
generic "PreReq".  This is what people have used for years to indicate
that A needs B to exist before it can be installed, usually so one can
run a scriptlet that uses B.

Does this help make sense of this patch?

Thanks.
Peter

On Fri, 2007-02-09 at 07:50 -0500, Jason Corley wrote:
> This is another one that could use some further details and explanation.
> 
> On 2/9/07, Paul Nasrat <pnasrat at redhat.com> wrote:
> > This patch reverts the change to disable prereqs, which are still used
> > as a hint for loop cutting.