Discussion related to cado-nfs

[eric.jeancolas@free.fr]

Dear Paul

I explain here what I did to test, to be sure I did what you expect.
I downloaded a new version of cado-nfs from 
https://gitlab.inria.fr/cado-nfs/cado-nfs/-/commits/7694b91283f11131ec54fe19c7d3ff8cdf8b97ad/
On my conputer, I erased previous cado directories, and I made a tar on 
cado-nfs-7694b91283f11131ec54fe19c7d3ff8cdf8b97ad.tar.gz and a make.
I issued the following command: ./cado-nfs.py 
181570647363941951922859674104963771103015312977807439204421953197794821673476296854978179746096739603508598016332617111965534228905323443567644055007324027034168949
 tasks.polyselect.import=18888_164.poly

The contents of 18888_164.poly is:
n: 
181570647363941951922859674104963771103015312977807439204421953197794821673476296854978179746096739603508598016332617111965534228905323443567644055007324027034168949
skew: 1.36
type: snfs
c0: -80
c5: 17
Y0: 1000000000000000000000000000000000
Y1: -1
# f(x) = 17*x^5-80
# g(x) = -x+1000000000000000000000000000000000
 
I reached the following steps:
Info:Generate Factor Base: Starting
Info:Generate Factor Base: Finished
Info:Generate Factor Base: Total cpu/real time for makefb: 22.1/19.6028
Info:Generate Free Relations: Starting
Info:Generate Free Relations: Found 1410662 free relations
Info:Generate Free Relations: Finished
Info:Generate Free Relations: Total cpu/real time for freerel: 462.44/319.124
Info:Lattice Sieving: Starting
Info:Lattice Sieving: We want 63458945 relation(s)
Info:Lattice Sieving: Adding workunit c165_sieving_30592187-30595000 to 
database
Info:Lattice Sieving: Adding workunit c165_sieving_30595000-30600000 to 
database

When I have a mismatch on a number, I don't reach Lattice Sieving.

So I stopped the process (Ctrl+C) just after that.

Just to recall here: the number 
181570647363941951922859674104963771103015312977807439204421953197794821673476296854978179746096739603508598016332617111965534228905323443567644055007324027034168949
 has been erroneously generated after some star removals.
The number to be factorized is 18888_164 = (17*10^164-8)/9 = 
(17*(10^33)^5-80)/90 = 
181*5706473639419519*22859674104963771103015312977807439204421953197794821673476296854978179746096739603508598016332617111965534228905323443567644055007324027034168949
( and eventually = 
181*5706473639419519*7159052365561448148227529365476870909708139900919265573*3193114526571981969989829734950032818678374603944682479503444963111309977900602192542410513
 )
The snfs polynomial has been generated accordingly.

Can you reproduce the problem, or is it related to my installation?

Best regards.

Eric


----- Mail original -----
De: "Paul Zimmermann" <Paul.Zimmermann@inria.fr>
À: "eric jeancolas" <eric.jeancolas@free.fr>
Cc: "pierrick gaudry" <pierrick.gaudry@loria.fr>, cado-nfs@inria.fr
Envoyé: Lundi 26 Avril 2021 14:51:07
Objet: Re: [cado-nfs] sqrt error

       Dear Eric,

are you sure you used the exact revision I mention below (git co 7694b91)?
I had to revert my commit later since it broke some tests.

Paul

> Date: Mon, 26 Apr 2021 13:18:12 +0200 (CEST)
> From: eric.jeancolas@free.fr
> Cc: pierrick gaudry <pierrick.gaudry@loria.fr>, cado-nfs@inria.fr
> 
> Dear Paul,
> I reinstalled cado and fiel timestamps are 26/04/2021 11:19.
> The problem is still the same, the number is not viewed as an error before 
> sieving is starting.
> Best regards.
> Eric
> 
> ----- Mail original -----
> De: "Paul Zimmermann" <Paul.Zimmermann@inria.fr>
> À: "eric jeancolas" <eric.jeancolas@free.fr>
> Cc: "pierrick gaudry" <pierrick.gaudry@loria.fr>, cado-nfs@inria.fr
> Envoyé: Lundi 26 Avril 2021 09:04:19
> Objet: Re: [cado-nfs] sqrt error
> 
>        Dear Eric,
> 
> please try the latest commit (7694b91) and please confirm it gives an error
> during the first check process.
> 
> Best regards,
> Paul