Cython compilation errors on Windows 10

First of all, has anyone run this on Windows 10 with positive results?
Because maybe this is the source of my problem.

When running I get this long list of error messages (this is only about 10% of them):

Any suggestions how to fix this on Windows 10, pyCharm, conda python 3.7?

> Error compiling Cython file:
> ------------------------------------------------------------
> ...
>
> from libc.stdlib cimport malloc, free
> from libc.stdio cimport sprintf
> from libc.string cimport strlen
>
> cimport c_region
> ^
> ------------------------------------------------------------
>
> Algos\libs\SiamMask\utils\pyvotkit\region.pyx:8:8: 'c_region.pxd' not found
>
> Error compiling Cython file:
> ------------------------------------------------------------
> ...
> RECTANGEL
> POLYGON
> MASK
>
> cdef class RegionBounds:
> cdef c_region.region_bounds* _c_region_bounds
> ^
> ------------------------------------------------------------
>
> Algos\libs\SiamMask\utils\pyvotkit\region.pyx:18:9: 'region_bounds' is not a type identifier
>
> Error compiling Cython file:
> ------------------------------------------------------------
> ...
> self._c_region_bounds.right = right
>
>
>
> cdef class Rectangle:
> cdef c_region.region_rectangle* _c_region_rectangle
> ^
> ------------------------------------------------------------
>
> Algos\libs\SiamMask\utils\pyvotkit\region.pyx:57:9: 'region_rectangle' is not a type identifier
>
> Error compiling Cython file:
> ------------------------------------------------------------
> ...
> self._c_region_rectangle.y,
> self._c_region_rectangle.width,
> self._c_region_rectangle.height)
>
> cdef class Polygon:
> cdef c_region.region_polygon* _c_region_polygon
> ^
> ------------------------------------------------------------
>
> Algos\libs\SiamMask\utils\pyvotkit\region.pyx:98:9: 'region_polygon' is not a type identifier
>
> Error compiling Cython file:
> ------------------------------------------------------------
> ...
> polygon2_ = Polygon(polygon2)
> cdef float only1 = 0
> cdef float only2 = 0
> # cdef c_region.region_polygon* c_polygon1 = polygon1._c_region_polygon
> # cdef c_region.region_polygon* c_polygon2 = polygon2._c_region_polygon
> cdef c_region.region_polygon* c_polygon1 = polygon1_._c_region_polygon
> ^
> ------------------------------------------------------------
>
> Algos\libs\SiamMask\utils\pyvotkit\region.pyx:176:9: 'region_polygon' is not a type identifier
>

Start by inspecting Algos\libs\SiamMask\utils\pyvotkit\region.pyx and the Cython build setup, then check why c_region.pxd is not found under Windows 10 with PyCharm and conda Python 3.7. Reproduce the compilation and trace the missing region type errors; done means the extension builds without these Cython errors.

Written by the indexing model from the issue text.