The Windows ARM64 nightly build (`mk_win_dist_cmake.py --arm64-only`)
was failing because the cmake-built `Microsoft.Z3` NuGet package was
produced without any native Windows DLL, causing the downstream dotnet
example build to fail.
## Root causes
- **Wrong DLL path in `Microsoft.Z3.csproj.in`**: Path included
`/$(_DN_CMAKE_CONFIG)/` (e.g., `.../RelWithDebInfo/libz3.dll`), but
`CMakeLists.txt` sets `CMAKE_RUNTIME_OUTPUT_DIRECTORY =
PROJECT_BINARY_DIR` with no config subdir. With Ninja single-config, the
DLL lands at `build-dir/libz3.dll`. The `Exists()` guard silently
excluded the DLL from the package.
- **Wrong runtime identifier**: ARM64 DLL was being packed under
`runtimes\win-x64\native` instead of `runtimes\win-arm64\native`.
- **Legacy copy fires for `net8.0`**: `Microsoft.Z3.targets` excluded
`netstandard`/`netcoreapp` but not modern TFMs like `net8.0`, so
`CopyToOutputDirectory` fired and failed trying to copy the absent
`win-x64` DLL.
## Changes
- **`src/api/dotnet/CMakeLists.txt`**: Introduce `Z3_DOTNET_WIN_RID`
cmake variable (`win-x64` / `win-x86` / `win-arm64`) derived from
`TARGET_ARCHITECTURE`; used at `configure_file` time.
- **`src/api/dotnet/Microsoft.Z3.csproj.in`**: Remove
`/$(_DN_CMAKE_CONFIG)` from the Windows DLL path; replace hardcoded
`runtimes\win-x64\native` with `runtimes\${Z3_DOTNET_WIN_RID}\native`.
- **`src/api/dotnet/Microsoft.Z3.targets`**: Add
`!$(TargetFramework.Contains('.'))` to the legacy-copy condition, which
correctly excludes `net5.0`/`net6.0`/`net7.0`/`net8.0` (all use dotted
TFMs) while keeping `net45`/`net472` etc.
- **`src/api/dotnet/Microsoft.Z3.props`**: Add explicit `arm64`
condition mapping `$(Platform) == 'arm64'` to
`runtimes\win-arm64\native\libz3.dll` for legacy .NET Framework ARM64
consumers.
Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: NikolajBjorner <3085284+NikolajBjorner@users.noreply.github.com>
