Parity export is generating incomplete exports

[tomusdrw]

(or import is working incorrectly)
Perhaps a flush is missing somewhere.

thread 'main' panicked at 'slice index starts at 8 but ends at 1', ../src/libcore/slice.rs:547
stack backtrace:
   1:     0x562778de849f - std::sys::backtrace::tracing::imp::write::h22f199c1dbb72ba2
   2:     0x562778df030d - std::panicking::default_hook::{{closure}}::h9a389c462b6a22dd
   3:     0x562778deec22 - std::panicking::default_hook::h852b4223c1c00c59
   4:     0x562778def218 - std::panicking::rust_panic_with_hook::hcd9d05f53fa0dafc
   5:     0x562778def0b2 - std::panicking::begin_panic::hf6c488cee66e7f17
   6:     0x562778deeff0 - std::panicking::begin_panic_fmt::hb0a7126ee57cdd27
   7:     0x562778deef71 - rust_begin_unwind
   8:     0x562778e2b68f - core::panicking::panic_fmt::h9af671b78898cdba
   9:     0x562778e2b804 - core::slice::slice_index_order_fail::h7cd01b7576762245
  10:     0x562778549bde - parity::blockchain::execute_import::h34f3f45debc92e58
  11:     0x5627785601b6 - parity::execute::he0b08fc297d7e520
  12:     0x56277856c131 - parity::main::h6e49bd258be47b41
  13:     0x562778df7dd6 - __rust_maybe_catch_panic
  14:     0x562778dee4a1 - std::rt::lang_start::h14cbded5fe3cd915
  15:     0x7fdb39062f44 - __libc_start_main
  16:     0x5627783cb86d - <unknown>
  17:                0x0 - <unknown>

[tomusdrw]

Most probably caused by redirecting output to a file instead of passing export target directly:

$ parity export --to 1000 > export.rlp # This is a wrong way of doing it
$ parity export --to 1000 export.rlp # This is a right way of doing it

[tomusdrw]

Possible solutions:

1. Make export file required parameter
2. Print Export completed and Loading config file: .. to stderr instead of stdout.