# Building

Make sure the required Android NDK platforms are installed, and the environment
variable `ANDROID_NDK_TOOLCHAIN_DIR` is configured correctly.

On Windows, this might be a path such as the following (NDK "Side by side" SDK tool):

```
%LOCALAPPDATA%\Android\Sdk\ndk\25.1.8937393\toolchains\llvm\prebuilt\windows-x86_64\bin
```