Fix packaged backend crashing on Windows at startup

backend/server.py

@@ -5,10 +5,19 @@
 package; this file stays here so PyInstaller (server.spec), run-app.bat and
 the Electron shell keep working unchanged.
 """
+import sys
 from datetime import datetime
 
-from app import create_app
-from app.services.ocr import tesseract_available
+# On Windows, stdout/stderr use the legacy code page (cp1252) when they are a
+# pipe, as when Electron launches the packaged backend. Printing any emoji
+# (startup banner, OCR progress messages) then raises UnicodeEncodeError and
+# kills the server, so force UTF-8 before anything else is imported.
+for _stream in (sys.stdout, sys.stderr):
+    if _stream is not None and hasattr(_stream, 'reconfigure'):
+        _stream.reconfigure(encoding='utf-8', errors='replace')
+
+from app import create_app  # noqa: E402
+from app.services.ocr import tesseract_available  # noqa: E402
 
 app = create_app()
 

backend/tests/test_entrypoint.py

@@ -0,0 +1,44 @@
+"""The real server.py entrypoint, started the way the Electron shell starts it."""
+import json
+import os
+import subprocess
+import sys
+import time
+import urllib.request
+
+BACKEND_DIR = os.path.dirname(os.path.dirname(os.path.abspath(__file__)))
+PORT = 5098
+
+
+def test_server_starts_with_legacy_windows_encoding_and_piped_output(tmp_path):
+    # Electron pipes stdout; on Windows that means cp1252, which cannot encode
+    # the emoji in the startup banner and used to crash the backend.
+    env = {
+        **os.environ,
+        'PYTHONIOENCODING': 'cp1252',
+        'LIBRADIGIT_PORT': str(PORT),
+        'LIBRADIGIT_DATABASE': str(tmp_path / 'db.sqlite'),
+        'LIBRADIGIT_UPLOAD_FOLDER': str(tmp_path / 'uploads'),
+        'LIBRADIGIT_ARCHIVE_FOLDER': str(tmp_path / 'Archive'),
+    }
+    proc = subprocess.Popen([sys.executable, 'server.py'], cwd=BACKEND_DIR, env=env,
+                            stdout=subprocess.PIPE, stderr=subprocess.STDOUT)
+    try:
+        health = None
+        deadline = time.time() + 30
+        while time.time() < deadline and proc.poll() is None:
+            try:
+                with urllib.request.urlopen(f'http://127.0.0.1:{PORT}/api/health', timeout=1) as res:
+                    health = json.load(res)
+                    break
+            except OSError:
+                time.sleep(0.3)
+        if health is None:
+            proc.kill()
+            output = proc.communicate(timeout=10)[0].decode('utf-8', 'replace')
+            raise AssertionError(f'backend did not start (exit {proc.returncode}):\n{output[-2000:]}')
+        assert health['status'] == 'healthy'
+    finally:
+        if proc.poll() is None:
+            proc.terminate()
+            proc.wait(timeout=10)

scripts/smoke-test-backend.ps1

@@ -25,10 +25,16 @@ try {
     $health = $null
     for ($i = 0; $i -lt 90 -and -not $health; $i++) {
         Start-Sleep -Seconds 1
+        # A crashed backend will never answer; stop waiting and show why.
+        if ($proc.HasExited) { break }
         try { $health = Invoke-RestMethod 'http://127.0.0.1:5001/api/health' } catch { }
     }
     if (-not $health) {
+        Write-Host '--- backend stdout ---'
+        Get-Content (Join-Path $env:TEMP 'backend-out.txt') -ErrorAction SilentlyContinue | Select-Object -Last 40
+        Write-Host '--- backend stderr ---'
         Get-Content (Join-Path $env:TEMP 'backend-err.txt') -ErrorAction SilentlyContinue | Select-Object -Last 40
+        if ($proc.HasExited) { throw "Backend exited with code $($proc.ExitCode) before becoming healthy" }
         throw 'Backend did not become healthy'
     }
     Write-Host "Health: $($health | ConvertTo-Json -Compress)"