For Gentoo, there is a static and dynamic tarball build available at the Link:

To use this build on  Gentoo Base Release 2.6, after downloading, unpack the tarball:

cd /your_chosen_path

mkdir cin

cd cin

tar -xJf /src/path//cinelerra-5.1-gentoo-20200202.x86_64-static.txz
tar -xJf /src/path/cinelerra-5.1-gentoo-20200202.x86_64.txz

Then to start up Cinelerra, just type in the following from a window in that directory path: