fix: Windows update entrypoint locking and idempotent releases

.github/workflows/release.yml

@@ -158,7 +158,14 @@ jobs:
           if [[ "${{ steps.version.outputs.prerelease }}" == "true" ]]; then
             PRERELEASE_FLAG="--prerelease"
           fi
-          gh release create "${{ github.ref_name }}" \
-            dist/* \
-            --generate-notes \
-            $PRERELEASE_FLAG
+          # If the release already exists (e.g. created manually), upload artifacts
+          # to it instead of failing.
+          if gh release view "${{ github.ref_name }}" &>/dev/null; then
+            echo "Release ${{ github.ref_name }} already exists, uploading artifacts…"
+            gh release upload "${{ github.ref_name }}" dist/* --clobber
+          else
+            gh release create "${{ github.ref_name }}" \
+              dist/* \
+              --generate-notes \
+              $PRERELEASE_FLAG
+          fi

src/conductor/cli/update.py

@@ -329,19 +329,9 @@ def run_update(console: Console) -> None:
 
     # On Windows, rename our exe out of the way so uv can write the new one.
     # Windows locks running executables but allows renaming them.
-    old_exe: Path | None = None
+    renamed_exes: list[tuple[Path, Path]] = []
     if sys.platform == "win32":
-        exe_path = _get_conductor_exe()
-        if exe_path and exe_path.exists():
-            old_exe = exe_path.with_suffix(".exe.old")
-            # Clean up leftover .old from a previous successful update
-            if old_exe.exists():
-                with contextlib.suppress(OSError):
-                    old_exe.unlink()
-            try:
-                exe_path.rename(old_exe)
-            except OSError:
-                old_exe = None  # rename failed; proceed anyway, uv will report the error
+        renamed_exes = _rename_windows_exes()
 
     try:
         proc = subprocess.run(cmd, capture_output=True, text=True)  # noqa: S603
@@ -350,16 +340,24 @@ def run_update(console: Console) -> None:
             console.print(f"[green]Successfully upgraded to v{version}[/green]")
             cache_path = get_cache_path()
             cache_path.unlink(missing_ok=True)
+        elif sys.platform == "win32" and "Failed to install entrypoint" in (proc.stderr or ""):
+            # On Windows, uv may fail to copy the entrypoint because the running
+            # executable is locked.  The package itself was installed successfully.
+            console.print(f"[green]Successfully upgraded to v{version}[/green]")
+            console.print(
+                "[dim]Note: restart your terminal for the update to take full effect.[/dim]"
+            )
+            cache_path = get_cache_path()
+            cache_path.unlink(missing_ok=True)
         else:
             console.print(f"[bold red]Upgrade failed[/bold red] (exit code {proc.returncode})")
             if proc.stderr:
                 console.print(f"[dim]{proc.stderr.strip()}[/dim]")
-            # On Windows, restore the original exe if uv failed to write a new one
-            if old_exe and old_exe.exists():
-                exe_path = old_exe.with_suffix("")  # .exe.old → .exe
-                if not exe_path.exists():
+            # On Windows, restore the original exe(s) if uv failed
+            for orig, backup in renamed_exes:
+                if backup.exists() and not orig.exists():
                     with contextlib.suppress(OSError):
-                        old_exe.rename(exe_path)
+                        backup.rename(orig)
     finally:
         # Clean up temp constraints file
         if constraints_path:
@@ -368,6 +366,58 @@ def run_update(console: Console) -> None:
                 constraints_path.parent.rmdir()
 
 
+def _rename_windows_exes() -> list[tuple[Path, Path]]:
+    """Rename conductor executables on Windows so ``uv`` can overwrite them.
+
+    Windows locks running executables, preventing overwrite.  Renaming is
+    still allowed, so we move them out of the way before ``uv tool install``.
+
+    We target both the executable found on ``PATH`` (the one currently running)
+    and the standard ``uv`` entrypoint location at ``~/.local/bin``, deduplicating
+    by resolved path.
+
+    Returns:
+        A list of ``(original_path, backup_path)`` tuples for later restoration.
+    """
+    renamed: list[tuple[Path, Path]] = []
+    seen: set[str] = set()
+    candidates: list[Path] = []
+
+    # 1. The exe on PATH (the one currently running)
+    exe_from_which = _get_conductor_exe()
+    if exe_from_which:
+        candidates.append(exe_from_which)
+
+    # 2. The standard uv entrypoint location
+    uv_bin_exe = Path.home() / ".local" / "bin" / "conductor.exe"
+    candidates.append(uv_bin_exe)
+
+    for exe_path in candidates:
+        if not exe_path.exists():
+            continue
+
+        # Deduplicate by resolved path (case-insensitive on Windows)
+        try:
+            key = str(exe_path.resolve()).lower()
+        except OSError:
+            continue
+        if key in seen:
+            continue
+        seen.add(key)
+
+        old_path = exe_path.with_suffix(".exe.old")
+        try:
+            # replace() overwrites an existing .old file, unlike rename() which
+            # fails on Windows when the destination already exists (e.g. from a
+            # previous interrupted update).
+            exe_path.replace(old_path)
+            renamed.append((exe_path, old_path))
+        except OSError:
+            pass  # rename failed; proceed, uv will report the error
+
+    return renamed
+
+
 def _download_constraints(tag_name: str, console: Console) -> Path | None:
     """Download and verify the constraints file for a release.
 

tests/test_cli/test_update.py

@@ -633,6 +633,41 @@ def test_unix_skips_rename(self, cache_dir: Path) -> None:
         output = buf.getvalue()
         assert "Successfully upgraded" in output
 
+    def test_windows_entrypoint_failure_reports_success(
+        self, cache_dir: Path, tmp_path: Path
+    ) -> None:
+        """On Windows, if uv installs the package but fails to copy the entrypoint,
+        report success with a restart note instead of failure."""
+        fake_exe = tmp_path / "conductor.exe"
+        fake_exe.write_text("fake")
+
+        cache_file = cache_dir / "update-check.json"
+        cache_file.write_text("{}")
+
+        c, buf = _make_console(is_terminal=True)
+        mock_proc = MagicMock()
+        mock_proc.returncode = 2
+        mock_proc.stderr = "error: Failed to install entrypoint\n  Caused by: failed to copy file"
+
+        with (
+            patch(
+                "conductor.cli.update.fetch_latest_version",
+                return_value=("99.0.0", "v99.0.0", "https://example.com"),
+            ),
+            patch("conductor.cli.update.sys.platform", "win32"),
+            patch("conductor.cli.update._get_conductor_exe", return_value=fake_exe),
+            patch("conductor.cli.update.subprocess.run", return_value=mock_proc),
+        ):
+            run_update(c)
+
+        output = buf.getvalue()
+        assert "Successfully upgraded" in output
+        assert "restart your terminal" in output
+        assert "Upgrade failed" not in output
+
+        # Cache should be cleared on partial success
+        assert not cache_file.exists()
+
 
 # ===================================================================
 # E3-T3: CLI-level tests