[setup topic/libsolv] Does "obsoletes:" work?
Tue Oct 24 20:09:00 GMT 2017
On 23/10/2017 18:43, Ken Brown wrote:
> On 10/23/2017 7:38 AM, Jon Turney wrote:
>> On 21/10/2017 21:18, Ken Brown wrote:
>>> On 10/20/2017 6:24 PM, Ken Brown wrote:
>>>> Have you ever tested the "obsoletes:" feature of setup/libsolv?Â I
>>>> tried adding an "obsoletes:" line to setup.ini, and it didn't seem
>>>> to have any effect.
>> It seems I tested it back in May, so it might well have broken since :)
>> Here's a very small test repo I've been using for some tests:
>> But yes, your patch looks like it's needed for it to work correctly...
>>> It turns out that it *is* working (after a minor fix, attached), but
>>> not always as I expect.Â Suppose A requires B and C obsoletes B.
>>> Then the "obsoletes" statement appears to have no effect.Â If I
>>> remove the dependence of A on B, then setup does propose uninstalling
>>> B and installing C.
>>> I guess the issue is that libsolv interprets "C obsoletes B" as
>>> "uninstall B and install C", and it won't uninstall B while something
>>> requires it.
>> The 'targeted' vs. 'untargeted' distinction is relevant here? Perhaps
>> we are doing the wrong one?
> Maybe.Â I've read and re-read the discussion of this in
> libsolv-bindings.txt, and I'm still not sure I understand it.
Yeah, the documentation is a bit impenetrable.
> But here's a simpler case where "obsoletes" isn't working as I expect.
> Using your test repo, in which A requires C and obsoletes B, I start
> with none of the packages installed.Â I choose B for installation
> (either interactively or on the command line), and B gets installed.Â If
> I now run setup a second time, A and C get installed and B gets
> I expected A and C to be installed on the first run.Â I don't think this
> has anything to do with targeted vs. untargeted, because that
> distinction is only relevant for updating installed packages.
I guess I had the opposite expectation (if I ask for A to be installed,
that's what should happen, because if it insists on upgrading it behind
my back there's no way to do that...)
The actual behaviour you mention fits what's described there pretty well.
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