Segfault with fraction field of multivariate ZZ polynomials as base ring of symmetric functions

[tscrim]

We have the following:

sage: SymmetricFunctions(FractionField(QQ['q','t']))
Symmetric Functions over Fraction Field of Multivariate Polynomial Ring in q, t over Rational Field
sage: SymmetricFunctions(FractionField(ZZ['q']))
Symmetric Functions over Fraction Field of Univariate Polynomial Ring in q over Integer Ring
sage: SymmetricFunctions(FractionField(ZZ['q','t']))
Segmentation fault (core dumped)

However, the last one works with Sage 7.3.

[tscrim]

I don't think this is caused by #12439 as the trace goes through libsingular.

[fbissey]

trace?

[tscrim]

Attached.

[jdemeyer]

Works for me on Sage 7.4.rc1:

sage: SymmetricFunctions(FractionField(QQ['q','t']))
Symmetric Functions over Fraction Field of Multivariate Polynomial Ring in q, t over Rational Field
sage: SymmetricFunctions(FractionField(ZZ['q']))
Symmetric Functions over Fraction Field of Univariate Polynomial Ring in q over Integer Ring
sage: SymmetricFunctions(FractionField(ZZ['q','t']))
Symmetric Functions over Fraction Field of Multivariate Polynomial Ring in q, t over Integer Ring

[tscrim]

That's good to know but slightly unsettling at the same time. I forced a rebuild of symmetrica once I saw this, but I'm now convinced that is not the problem. Maybe it's something with the compiler? I used gcc 5.4.0 to build Sage. Although I guess we should wait to try and diagnose this further once 7.5.beta0 comes out, which should have Singular 4.

[tscrim]

Hmm...this now is working for me now that I bumped to 7.4.rc2. I might have just done something to mess up my install when testing stuff... So perhaps we should just close this as invalid.