Revision history [back]

This is definitely a bug, thanks for reporting, it is now trac ticket 30702.

As for tracking a minimal example, it seems that when a finite field uses givaro as a backend, it is possible to deal with polynomial rings in a single variable (generic Sage implementation) :

sage: F = GF(3, impl='givaro')
sage: F
Finite Field of size 3
sage: type(F)                                                                                                                                                                                                
<class 'sage.rings.finite_rings.finite_field_givaro.FiniteField_givaro_with_category'>

sage: R.<a0> = PolynomialRing(F)
sage: type(R)
<class 'sage.rings.polynomial.polynomial_ring.PolynomialRing_dense_finite_field_with_category'>                                                                                                                                                                           
sage: F(R(2))
2

But dealing with multivariate polynomial ring (whose implementation relies on libsingular) leads to segfaults:

sage: R.<a0,a1> = PolynomialRing(F)
sage: type(R)
<class 'sage.rings.polynomial.multi_polynomial_libsingular.MPolynomialRing_libsingular'>
sage: F(R(2))
....
Segmentation fault