Re: Big GOTCHAs WITH forprime()

[Charles Greathouse <crgreathouse@gmail.com>]

It's a no-repro for me on 2.16.2 29115-f22e516b23 on WSL 2/Ubuntu 23.10. The immediate segfault version gives me

[190334138131456478.73170673847198486328, 190334138366361066.68292668461799621582, 15235, 66]
[190334138131456478.73170673847198486328, 190334138307634919.69512169808149337769, 15436, 65]
[190334138131456478.73170673847198486328, 190334138263590309.45426795817911624908, 15754, 64]
[190334138131456478.73170673847198486328, 190334138230556851.77362765325233340263, 15631, 63]
[190334138131456478.73170673847198486328, 190334138205781758.51314742455724626780, 16474, 62]
[190334138131456478.73170673847198486328, 190334138187200438.56778725303593091667, 16448, 61]
[190334138131456478.73170673847198486328, 190334138173264448.60876712439494440332, 16148, 60]
[190334138131456478.73170673847198486328, 190334138162812456.13950202791420451831, 15888, 59]
[190334138131456478.73170673847198486328, 190334138154973461.78755320555364960455, 15956, 58]
[190334138131456478.73170673847198486328, 190334138149094216.02359158878323341923, 16085, 57]
[190334138131456478.73170673847198486328, 190334138144684781.70062037620542128025, 16290, 56]
[190334138131456478.73170673847198486328, 190334138141377705.95839196677206217601, 17247, 55]
[190334138131456478.73170673847198486328, 190334138138897399.15172065969704284782, 16921, 54]
[190334138131456478.73170673847198486328, 190334138137037169.04671717939077835169, 16745, 53]
[190334138131456478.73170673847198486328, 190334138135641996.46796456916107997959, 17014, 52]
[190334138131456478.73170673847198486328, 190334138134595617.03390011148880620051, 16793, 51]
[190334138131456478.73170673847198486328, 190334138133810832.45835176823460086620, 18051, 50]
[190334138131456478.73170673847198486328, 190334138133222244.02669051079394686547, 17372, 49]
[190334138131456478.73170673847198486328, 190334138132780802.70294456771345636492, 16328, 48]
[190334138131456478.73170673847198486328, 190334138132449721.71013511040308848951, 16361, 47]
[190334138131456478.73170673847198486328, 190334138132201410.96552801742031258296, 16889, 46]
[190334138131456478.73170673847198486328, 190334138132015177.90707269768323065304, 16960, 45]

and the original gives

[190333000000000000.00000000000000000000, 190334500000000000.00000000000000000000, 16614, 97]
[190333000000000000.00000000000000000000, 190334125000000000.00000000000000000000, 15860, 96]
[190333000000000000.00000000000000000000, 190333843750000000.00000000000000000000, 16222, 95]
[190333000000000000.00000000000000000000, 190333632812500000.00000000000000000000, 15774, 94]
[190333000000000000.00000000000000000000, 190333474609375000.00000000000000000000, 15768, 93]
[190333000000000000.00000000000000000000, 190333355957031250.00000000000000000000, 16072, 92]
[190333000000000000.00000000000000000000, 190333266967773437.50000000000000000000, 16555, 91]
[190333000000000000.00000000000000000000, 190333200225830078.12500000000000000000, 16378, 90]
[190333000000000000.00000000000000000000, 190333150169372558.59375000000000000000, 16610, 89]
[190333000000000000.00000000000000000000, 190333112627029418.94531250000000000000, 17012, 88]
[190333000000000000.00000000000000000000, 190333084470272064.20898437500000000000, 16828, 87]
[190333000000000000.00000000000000000000, 190333063352704048.15673828125000000000, 16711, 86]
[190333000000000000.00000000000000000000, 190333047514528036.11755371093750000000, 18670, 85]
[190333000000000000.00000000000000000000, 190333035635896027.08816528320312500000, 16417, 84]
[190333000000000000.00000000000000000000, 190333026726922020.31612396240234375000, 15564, 83]
[190333000000000000.00000000000000000000, 190333020045191515.23709297180175781250, 16643, 82]
[190333000000000000.00000000000000000000, 190333015033893636.42781972885131835938, 16731, 81]
[190333000000000000.00000000000000000000, 190333011275420227.32086479663848876953, 16938, 80]
[190333000000000000.00000000000000000000, 190333008456565170.49064859747886657715, 16792, 79]

On Wed, Jan 24, 2024 at 6:32 PM Ilya Zakharevich <nospam-abuse@ilyaz.org> wrote:

On Wed, Jan 24, 2024 at 12:07:12PM +0100, Bill Allombert wrote:
> On Wed, Jan 24, 2024 at 01:08:38AM -0800, Ilya Zakharevich wrote:
> > Anyway — unless you want (the dubious fun of) running the binary
> > search yourself — you missed the second part of the bug report
> >    https://pari.math.u-bordeaux.fr/cgi-bin/bugreport.cgi?bug=2520#10
> > which lists the command which fails immediately on my system.
>
> Indeed, but so far nobody else has been able to reproduce this.
>
> On linux:
>
> [190333000000000000.00000000000000000000,190334500000000000.00000000000000000000,10354,97]

I REALLY wonder what is so wrong with my prose that “nobody else” can
read it…  Just in case, I repeat the reference for the third time:

  https://pari.math.u-bordeaux.fr/cgi-bin/bugreport.cgi?bug=2520#10

Thanks,
Ilya