I was was assisting VY2HF install CubicSDR with his RSP1 and ended up creating a script to automate the process and thought I would share it here. I started with K3OS’s rtf file, found a couple of typos, changed a few things and make a bash script out of it. This script installs Hamlib 4.0 which supports many newer rigs. All activity is under /usr/pi/src and has been tested on 3 different fresh Raspbian Buster 2020-08-20-raspios-buster-armhf-full.img

Instructions
Download CubicSDR_install.sh using the browser on the pi to the Downloads directory

Download the correct API driver from the SDRPlay website to the Downloads directory. This script is assuming the file is called SDRplay_RSP_API-ARM32-3.07.2.run

Open a terminal and type:
cd ~/Downloads
bash CubicSDR_install.sh

The first thing it does is install the API and you will have to scroll and agree to the license. Answer yes to any questions.
The script will now download, build and install hamlib, all the needed Soapy components and then CubicSDR. It will pause after each section and allow you to continue if no errors or break out if there is a problem.
If you make it to the end OK just type CubicSDR in the terminal and you should be good to go.