/* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open,
dup2 (fd, fd) returns 0, but all further attempts to use fd in
future dup2 calls will hang. */
/* If fd is closed, mingw hangs on dup2 (fd, fd). If fd is open,
dup2 (fd, fd) returns 0, but all further attempts to use fd in
future dup2 calls will hang. */