[Debian-science-sagemath] Sage 7.6 testing migration blocked by giac

[Tobias Hansen]

On 06/22/2017 12:14 PM, Tobias Hansen wrote:
> On 06/22/2017 10:03 AM, Ximin Luo wrote:
>> Tobias Hansen:
>>> On 06/20/2017 03:44 PM, Ximin Luo wrote:
>>>> [..]
>>>>
>>>> There's some more detailed info here which is where I got that from:
>>>>
>>>> https://www.debian.org/devel/testing
>>>>
>>>> It talks about "breaks" in the general sense and mentions when Depends: gets broken. I assumed this also includes explicit Breaks:, but it doesn't mention this specifically. Unfortunately number (4) and (5) reasons don't get displayed explicitly on the "migration excuses" page.
>>> Even if britney notices conflicts created by Breaks, this is not that
>>> well suited for what we want to do, because Breaks is only for relations
>>> between binary packages, not source packages. For some packages I think
>>> it's not even possible to create a conflict.
>>>
>>> Take for example a library, fplll.
>>> No binary package from sagemath depends on libfplll-dev, so it's not
>>> possible to create a conflict by adding "Breaks: sagemath (<< 8.0~)" to
>>> libfplll-dev.
>>> No binary package from sagemath 7.6 depends on libfplll3 (they depend on
>>> libfplll2), so it's not possible to create a conflict by adding "Breaks:
>>> sagemath (<< 8.0~)" to libfplll3.
>>>
>>> However, if this fplll package migrates to testing, it's no longer
>>> possible to build sagemath 7.6 in testing.
>>>
>> I think in this situation, britney would still prevent the migration because libfplll2 would no longer be available to be installed in testing, implicitly breaking sagemath 7.6. That would be the correct behaviour anyway.
>>
>> BTW I've updated giac and it has built sucessfully in those missing architectures. The excuses page says it'll take 5 more days to migrate.
>>
>> X
>>
> We can try to learn more by looking at why eclib and singular are not
> migrating to testing at the moment.
>
> The eclib update changes soname from libec2 to libec3, singular has the
> same packages as before.
>
> We have this in https://release.debian.org/britney/update_output.txt
>
> trying: eclib
> skipped: eclib (0, 2, 31)
>     got: 37+0: a-6:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
>     * amd64: python-sagetex, sagemath, sagemath-jupyter, sagetex
>
> trying: singular
> skipped: singular (0, 8, 25)
>     got: 37+0: a-6:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
>     * amd64: python-sagetex, sagemath, sagemath-jupyter, sagetex
>
> Any idea how to read this?
>
> Also what you wrote in the last mail isn't true, pynac migrated despite the new soname. It still appears in the output because libpynac2 cannot be removed due to sagemath:
>
> Removing packages left in testing for smooth updates (2):
>   libpynac2: i386 amd64
> start: 33+0: a-2:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
> orig: 33+0: a-2:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
> recur: []  2/0
> trying: -libpynac2/i386
> skipped: -libpynac2/i386 (0, 0, 1)
>     got: 37+0: a-2:i-30:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
>     * i386: python-sagetex, sagemath, sagemath-jupyter, sagetex
> trying: -libpynac2/amd64
> skipped: -libpynac2/amd64 (0, 1, 0)
>     got: 37+0: a-6:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
>     * amd64: python-sagetex, sagemath, sagemath-jupyter, sagetex
>  finish: []
> endloop: 33+0: a-2:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
>     now: 33+0: a-2:i-26:a-0:a-0:a-0:m-0:m-4:m-0:p-0:s-1
>
> Best,
> Tobias
>


The reason that singular doesn't migrate is that sagemath 7.4 has
depends like

singular (<< 1:4.1).

I don't know however what is the difference between pynac and eclib that caused pynac to migrate but not eclib. They both have a new soname.

One solution to prevent premature testing migrations would be to add maximal versions for dependencies (like the singular example above) to sagemath.
That would mean that before migrating a bunch of updates for a new sage version from experimental to unstable,
we would add the maximal versions to the old sagemath in unstable and wait for this to migrate to testing.
It's a bit annoying though.

Best,
Tobias