limit of diff where a is a symbol

[vvavrychuk]

>> syms f(x)
>> syms y
>> limit(diff(f),y)
error: Python exception: NotImplementedError: Don't know how to calculate the mrv of 'Subs(Derivative(f(_p), _p), _p, y + 1/_p)'
    occurred at line 10 of the Python code block:
    return _op(*_ins)
error: called from
    pycall_sympy__ at line 179 column 7
    elementwise_op at line 102 column 5
    limit at line 92 column 5

If limit approaches a constant, it is fine

>> limit(diff(f),0)
ans = (sym)

  / d        \|
  |---(f(xi))||
  \dxi       /|xi=0

[vvavrychuk]

opened upstream issue sympy/sympy#27143