CADO-NFS IndexError

[arakelov]

Hello,
I've just compiled cado-nfs on Ubuntu 18.04 and when trying to factor an 85 digit number I got this error:

...
Traceback (most recent call last):
File "./cado-nfs.py", line 122, in <module>
factors = factorjob.run()
File "./scripts/cadofactor/cadotask.py", line 5958, in run
last_status, last_task = self.run_next_task()
File "./scripts/cadofactor/cadotask.py", line 6050, in run_next_task
return [task.run(), task.title]
File "./scripts/cadofactor/cadotask.py", line 2289, in run
n, self.best_polys[0].MurphyE,
IndexError: list index out of range

Can you please help?
Thanks!

[VBCurtis]

I've never tried factoring a number that small with CADO, so I'm not sure whether to guess at compilation problems, or an issue with the parameters file for a C85 (for instance, the params file may not be updated since some part of CADO changed requiring a parameter to have a different name/setting).

I'd try a C100 or so and see if the error is identical.

[arakelov]

Thanks for the response. Other examples give the same error.
I compiled a previous tarball (cado-nfs-2.3.0.tar.gz) and the error was gone.

I'm not sure if I did right for getting the current version:
git clone https://gitlab.inria.fr/cado-nfs/cado-nfs.git

Maybe I got a unstable snapshot. Sorry if it was that.
Thanks!

[EdH]

If it is of help, I have a thread on "How I Install CADO-NFS onto my Ubuntu Machines" that I use whenever doing a new install.


Edit: You might check the special note about 18.04 on the page shown above. Basically, I had to install python to get it to run. The 18.04 only had python3.

[arakelov]

In fact, I used your notes for my installation!
The line "git clone https://scm.gforge.inria.fr/anonscm/git/cado-nfs/cado-nfs.git" is outdated; now I think it should be "git clone https://gitlab.inria.fr/cado-nfs/cado-nfs.git"

Thanks for the help!

[EdH]

Originally Posted by arakelov

In fact, I used your notes for my installation!
The line "git clone https://scm.gforge.inria.fr/anonscm/git/cado-nfs/cado-nfs.git" is outdated; now I think it should be "git clone https://gitlab.inria.fr/cado-nfs/cado-nfs.git"

Thanks for the help!

Thanks for that update. I've made the change and am in the process of trying it with one of my 18.04 machines. This machine already has a working copy of CADO-NFS, though, so this isn't from scratch. I'll let you know if it runs or not a little later.


Edit: It "seemed" to run fine with the README sample. However "seemed" is because the machine crashed after it came up with the factors. I rebooted and am now testing a c85 from factordb.


Edit2: It factored the c85 without issue.

[arakelov]

Thanks a lot for the info. I'll check again for missing packages/dependencies/whatever and try to compile a new fresh snapshot.

Best regards and happy factoring!