Hanging on s390x with singular 4.2.1

[d-torrance]

This is currently preventing the Ubuntu singular package from migrating from "proposed" to "release" to be part of the next LTS release. From https://autopkgtest.ubuntu.com/results/autopkgtest-jammy/jammy/s390x/q/qepcad/20211216_201020_bda39@/log.gz:

autopkgtest [17:23:26]: test command1: qepcad < debian/tests/positive-semidefinite && qepcad < debian/tests/triangles && qepcad < debian/tests/anai && qepcad < debian/tests/edge-square-product && qepcad < debian/tests/quartic && qepcad < debian/tests/hong-liska-steinberg && cad2d < debian/tests/cad2d
autopkgtest [17:23:26]: test command1: [-----------------------
=======================================================
                Quantifier Elimination                 
                          in                           
            Elementary Algebra and Geometry            
                          by                           
      Partial Cylindrical Algebraic Decomposition      

      Version B 1.74, Thu Feb 25 14:48:53 EST 2021

                          by                           
                       Hoon Hong                       
                  (hhong@math.ncsu.edu)                

With contributions by: Christopher W. Brown, George E. 
Collins, Mark J. Encarnacion, Jeremy R. Johnson        
Werner Krandick, Richard Liska, Scott McCallum,        
Nicolas Robidoux, and Stanly Steinberg                 
=======================================================
Enter an informal description  between '[' and ']':
[ Computes the "not" of "is p positive semidefinite?" ]Enter a variable list:
(w,z,x,y)Enter the number of free variables:
0
Enter a prenex formula:
(F w)(F z)(F x)(F y)[
w^6 + 2 z^2 w^3 + x^4 + y^4 + z^4 + 2 x^2 w + 
2 x^2 z + 3 x^2 + w^2 + 2 z w + z^2 + 2 z + 2 w + 1 < 0
].

=======================================================

Before Normalization >
finish
autopkgtest [20:10:06]: ERROR: timed out on command "su -s /bin/bash ubuntu -c set -e; export USER=`id -nu`; . /etc/profile >/dev/null 2>&1 || true;  . ~/.profile >/dev/null 2>&1 || true; buildtree="/tmp/autopkgtest.WeBj3A/build.Emz/src"; mkdir -p -m 1777 -- "/tmp/autopkgtest.WeBj3A/command1-artifacts"; export 

I've confirmed that this is also an issue in Debian unstable on an s390x porterbox. Note that s390x is big endian, so that may be related.

[d-torrance]

Never mind -- this is actually a Singular issue:

                     SINGULAR                                 /  Development
 A Computer Algebra System for Polynomial Computations       /   version 4.2.1
                                                           0<
 by: W. Decker, G.-M. Greuel, G. Pfister, H. Schoenemann     \   May 2021
FB Mathematik der Universitaet, D-67653 Kaiserslautern        \  Debian 1:4.2.1-p2+ds-5
> ring r=32003,(x,y,z),dp;
> poly f=x3+y5+z2;
> f;
   ? `f` is undefined
   ? error occurred in or before STDIN line 3: `f;`