How to Install Older Versions of Ruby

The problem is with RVM and renv and not with asdf, so my first suggestion is to change to asdf

if you keep with RVM: install older versions of ruby <2.3 with support for openssl 1.0x you can follow these instructions:

# before you install command line tools and gcc
xcode-select --install
brew install gcc

# installation procedure
cd /usr/local/src
curl -O https://www.openssl.org/source/openssl-1.0.2t.tar.gz
tar xzf openssl-1.0.2t.tar.gz
cd openssl-1.0.2t
./Configure darwin64-x86_64-cc
make
sudo make install
export LDFLAGS=“-L/usr/local/ssl/lib”
export CPPFLAGS=“-I/usr/local/ssl/include”
export PKG_CONFIG_PATH=“/usr/local/ssl/lib/pkgconfig”
rvm reinstall 2.3.8 --with-openssl-dir=/usr/local/ssl --with-openssl-include=/usr/local/ssl/include