On cygwin, py3k aborts if lanches it via symbolic link.

//////////// message beg /////////////////////////

Could not find platform independent libraries <prefix>
Could not find platform dependent libraries <exec_prefix>
Consider setting $PYTHONHOME to <prefix>[:<exec_prefix>]
Fatal Python error: Py_Initialize: can't initialize sys standard streams
ImportError: No module named encodings.utf_8
Aborted (core dumped)

//////////// message end  /////////////////////////

This is because mbstowcs() on cygwin is broken, so _Py_wreadlink() in
Modules/getpath.c is also broken. I'll attach two patches to fix this. I
don't know which is better.

http://man.he.net/man3/readlink says: "Conforming applications should
not assume that the returned contents of the symbolic link are
null-terminated"

cygwin is not broken, but very (too much?) conforming in this case ;-)

I think your second patch is the correct one, just keep the "return
(int)r1;" because the return value is stored in a "linklen" variable.

Oh, I misunderstood the reason...
readlink() can return non-null-terminated string, so mbstowcs may
convert illegual memory area. I've attached py3k_getpath_v3.patch.

Your patch is OK for me. Please apply!

Thanks, fixed in r66338(py3k).