The "autobuild" feature enabled in Gemini3D since near the beginning of enabling CMake for it ~ 2019 had grown to beyond useful purpose. So many packages were in the hierarchy that rebuilding Gemini3D from scratch was becoming onerous.

We stripped out the autobuild features into https://github.com/gemini3d/external, which can either build all libraries, or just the missing/broken libraries, as how autobuild used to work within Gemini3D.
The user can thus provide a combination of system/self-built/autobuild libraries via this separate repo, to avoid having to build all those libraries when a complete Gemini3D rebuild is desired.