No Android 2.2 support after Unity 3.2 update?

After installing the latest update to Unity, I started getting a build error "Android SDK does not include any platforms! Did you run Android SDK setup to install the platform(s)? Minimum platform required for build is Android 2.3 (API level 9)"

I had previously been able to build and run my Unity apps on my HTC EVO 4G running Android 2.2 (with a 2.3 update kinda-maybe-promised-but-still-not-here-yet).

Is there a way to restore Unity compatibility with Android SDK API level 8?

turns out this was caused by there not being any Android SDK installed on my system, or perhaps just not being the latest version. Somehow, I had been able to build for Android without it before, and now it appears to be a requirement for Unity to build to Android.