doc: Increase required cython version: 0.24 -> 0.26.1
@@ -164,7 +164,7 @@ If you want to use cuDNN or NCCL installed in other directory, please use ``CFLA
Install CuPy for developers
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
-CuPy uses Cython (>=0.24).
+CuPy uses Cython (>=0.26.1).
Developers need to use Cython to regenerate C++ sources from ``pyx`` files.
We recommend to use ``pip`` with ``-e`` option for editable mode::
