If you use shutil.move and the resulting path name is too long, it will raise an Rpython error that will crash the entire interpreter instead of raising any kind of exception. Was really annoying to figure out when this happened in a really large script and would not print out any kind of traceback to tell me where the error was happening. It took quite a bit of debugging and testing to determine the line where the issue was occuring, and the fact that it was being caused by a file path being too long. Trying to manually do the copy outside of pypy told me the pathname was too long.
Issue #2895 resolved