In Sage 9.1.beta0, we have

sage: M = Manifold(2, 'M')
sage: M.set_calculus_method('sympy')
sage: X.<x,y> = M.chart()
sage: X.calculus_method()
Available calculus methods (* = current):
 - SR (default) (*)
 - sympy

while the current calculus method on the chart X should be sympy, as requested for any chart on M by M.set_calculus_method('sympy').
Prior to Sage 8.8, it was OK. The bug was actually introduced in #27601 (merged in Sage 8.8.beta1) by the accidental removal of the line

self._calculus_method = method

in the code of set_calculus_method().

This ticket fixes it by restoring the missing line.

CC: @tscrim

Component: geometry

Author: Eric Gourgoulhon

Branch/Commit: 02f0418

Reviewer: Travis Scrimshaw

Issue created by migration from https://trac.sagemath.org/ticket/29021