If a Cython project (named "junk" in this case) has the line from cpython cimport array in the pyx or pxd file, it compiles fine with PyPy 5.8, but dies as soon as the the compiled project is imported:

Traceback (most recent call last):
  File "test.py", line 1, in <module>
    import junk
  File "pypy5.8/site-packages/Cython/Includes/cpython/array.pxd", line 58, in init junk
    ctypedef class array.array [object arrayobject]
ValueError: array.array has the wrong size, try recompiling. Expected 24, got 64

I'm testing on a Mac with PyPy 5.8.0 installed via Homebrew. I tested this with Cython 0.26 and Cython master as of 90fa8d7.