integrate on polytopes with latte : result is always equal 0

edit

I can replicate the observed bug in Ubuntu 22.04.2 LTS (jammy) with

• conda-installed SageMath 10.0
• conda-installed LattE integrale 1.7.5.

But specifying algorithm=latte as in @FrédéricC's comment gives the correct integral.

sage: from sage.features.latte import Latte
sage: Latte().is_present()
FeatureTestResult('latte_int', True)

sage: P = polytopes.cube()
sage: x, y, z = polygens(QQ, names='x, y, z')
sage: f = x^2 * y^2 * z^2

sage: P.integrate(f)
0
sage: P.integrate(f, algorithm='latte')
8/27

The first example in the documentation of P.integrate, accessed with P.integrate?, or found at

• https://github.com/sagemath/sage/blob...

reads:

  sage: P = polytopes.cube()
  sage: x, y, z = polygens(QQ, 'x, y, z')
  sage: P.integrate(x^2*y^2*z^2)    # optional - latte_int
  8/27

That example should probably be fixed to use algorithm=latte.

Without algorithm=latte, I think Sage checks whether LattE is available, and if so uses it. But apparently that detection fails in the conda setup.

In any case, at some point a "not implemented" error should be raised rather than returning a wrong result.

I'm curious

• why the bug is observed with conda-installed Sage and LattE, but not in other setups
• what code path leads to returning zero as an answer