Hi,
the sonic pi team is working hard to simplify the install for the next version.
if you want to install the spi3.2dev version corresponding to the 002157 commit, you can follow these instructions.
It works for me on ubuntu 18.04.04.
mkdir spi3.2-ubuntu-18.04.04-working-procedure
cd spi3.2-ubuntu-18.04.04-working-procedure/
git clone https://github.com/samaaron/sonic-pi
cd sonic-pi/
git reset --hard 002157a607a37bdbf64d1f7daf563347c26bd361
cd app/gui/qt/
./build-ubuntu-18-04
cd ..
cd ..
cd ..
cd bin/
./sonic-pi
May it helps.