http://bugs.python.org/issue17797 http://connect.microsoft.com/VisualStudio/feedback/details/785119/ Visual Studio 2013 changed return value for fileno function that breaks when python tries to check/setup stdin/out/err GetStdHandle on Windows XP behaves contrary to the documentation... MSVC 14.0 fixed this bug. diff -ru python3.orig/Python/pylifecycle.c python3/Python/pylifecycle.c --- python3.orig/Python/pylifecycle.c 2015-07-05 18:50:08.000000000 +0200 +++ python3/Python/pylifecycle.c 2015-07-26 20:01:23.563082638 +0200 @@ -1065,15 +1065,30 @@ static int is_valid_fd(int fd) { - int dummy_fd; if (fd < 0 || !_PyVerify_fd(fd)) return 0; - _Py_BEGIN_SUPPRESS_IPH - dummy_fd = dup(fd); - if (dummy_fd >= 0) - close(dummy_fd); - _Py_END_SUPPRESS_IPH - return dummy_fd >= 0; + +#if defined(MS_WINDOWS) && defined(HAVE_FSTAT) && defined(_MSC_VER) && (_MSC_VER >= 1700 && _MSC_VER < 1900) + /* dup (DuplicateHandle) doesn't say fd is a valid *file* handle. + * It could be a current thread pseudo-handle. + */ + { + struct stat buf; + if (fstat(fd, &buf) < 0 && (errno == EBADF || errno == ENOENT)) + return 0; + else + return 1; + } +#else + { + int dummy_fd = dup(fd); + _Py_BEGIN_SUPPRESS_IPH + if (dummy_fd >= 0) + close(dummy_fd); + _Py_END_SUPPRESS_IPH + return dummy_fd >= 0; + } +#endif } /* Initialize sys.stdin, stdout, stderr and builtins.open */