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

[Ken Brown]

On 12/13/2017 5:31 PM, Ken Brown wrote:
> On 12/13/2017 1:05 PM, Achim Gratz wrote:
>> Ken Brown writes:
>>> 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'.
>>
>> I don't think there is a default in this case.  I also see in zypper
>> that the order of the proposed solutions (there can be way more than two
>> if the dependencies are more complicated) is not always the same, so
>> there is no preference implied by the order as well.
>>
>>> 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.
>>
>> That solution unfortunately isn't always the one that causes the least
>> amount of transactions or even the least amount of breakage.
> 
> That may be true, but I still think it's a reasonable default.  The user 
> doesn't have to accept it.  Also, it's consistent with what setup 
> currently does, so it won't surprise anyone.
> 
> The attached patch attempts to implement my suggestion.

I should add that this patch is only a band aid.  Eventually, as we 
start to use more of libsolv's capabilities, we will have to find a way 
for users to choose a solution.

Ken