Re: [PATCH setup 00/14] Use libsolv, solve all our problems... (WIP)

[Ken Brown <kbrown@cornell.edu>]

On 12/5/2017 9:32 AM, Jon Turney wrote:
> It seems we're missing something to actually apply the default solution, 
> so "accept default solutions" makes no changes, at the moment. (looks 
> like we have to do this ourselves with solver_take_solution() ?)

I've just looked at this again, and I'm not sure what's happening.

Here's what I tried:  I had two installed packages A and B, where A 
requires B.  I tried to uninstall B and got the expected problem report 
telling me that A requires B.  The solutions presented were

1. Uninstall A.
2. Don't uninstall B.

On the surface, it would seem that libsolv chose 2 by default, because 
it returned an empty transaction list.  This was reflected in the log 
and was also clear when I selected 'Back'.

On the other hand, maybe libsolv's default was to do nothing, and it's 
just a coincidence that this coincided with solution 2.  This could have 
tricked me into thinking that libsolv chose a default solution.

> Also, in the dependency problem report, we should identify which of the 
> possible solutions is the default one, so it's clearer what "accept 
> default solutions" is going to do.

Is there in fact a default solution?  I skimmed through problems.c in 
the libsolv sources, and I didn't see any mention of a default solution.

Maybe we have to deal with this situation ourselves.  Whenever a problem 
involves a missing dependency, we could choose as default solution the 
one that installs/keeps the dependent package, as is currently done.

Ken