Two Windows-only backend crash classes, one boundary (process spawn/stdio):
forrtl: error (200) (#1153 and the crash markers in #1155/#1152): MKL's
Intel Fortran runtime installs a console CTRL handler that aborts the
whole backend (exit 2 / 0xC000013A) when a console CLOSE/LOGOFF event
reaches it. The backend was spawned with no console isolation, so OS
console events could reach it mid-session. Now:
- the desktop shell spawns the backend with CREATE_NO_WINDOW |
CREATE_NEW_PROCESS_GROUP (no console → no console events, stdio is
piped anyway) and sets FOR_DISABLE_CONSOLE_CTRL_HANDLER=1;
- backend/main.py setdefaults the same var before torch/numpy can load
MKL, covering scripts/run.sh and bare uvicorn launches too.
'charmap' codec can't encode (#1155): kittentts print()s the user's text
on every generate; on Windows the child's stdout is cp1252, so Vietnamese
text raised UnicodeEncodeError and surfaced as a bogus '400 Bad Request'.
The process-wide SafeFileWrapper only swallowed OSError (its EPIPE job).
Now:
- stdio is reconfigured to UTF-8 (errors=backslashreplace) at startup;
- SafeFileWrapper also swallows UnicodeError — logs are best-effort,
synthesis is not;
- the shell sets PYTHONUTF8=1 for the child (Windows→parity with
macOS/Linux; process env wins for power users);
- the crash-log append opens with encoding=utf-8 so tracebacks carrying
user text can't re-trip the same codec.
Regression tests: tests/test_windows_stdio_guards.py (cp1252 stream write
must not raise; main must set the Fortran guard + UTF-8 stdio).
Co-Authored-By: Claude Fable 5 <noreply@anthropic.com>
