"The 'IF' statement is deprecated and will be removed in a future Cython version"

[PeterMeisrimelModelon]

(For visibility)

The build output is littered with the warning The 'IF' statement is deprecated and will be removed in a future Cython version. Consider using runtime conditions or C macros instead., which is from the conditional compilation based on the Sundials version used.

There does not seem to be a straight-forward alternative right now and there is no timeline for actually removing it as of now. See further: cython/cython#4310.

Also see comment in particular, current plan is to ignore the warning and monitor the developments in Cython.