RVM

Had a bunch of random issues with my Mac when trying to install RVM and compile certain rubies.

Get the following path with this brew command and then pass it into the stuff that is compiling ruby with either this environment variable or by specifying --with-openssl-dir when running rvm install.

brew --prefix openssl@1.1
export RUBY_CONFIGURE_OPTS=--with-openssl-dir=<openssl path>

It also seemed necessary to do rvm install with the --with-gcc option because of an error compiling sassc in one of my rails projects.

Another trick that saved the day was deleting whatever developer command line tools I had and reinstalling with:

rm -rf /Library/Developer/CommandLineTools
xcode-select --install

Finally - installing a certain gem in a certain rails project was failing due to a compiler error (probably wrong version of either gcc or LLVM, resolved by the above developer tools reinstall, but I’m keeping this here in case it helps a future me). These -Wno-error=<error name> flags allowed the compiler to kindly shut up and compile the native extension please and thank you very much etc :)

gem install nio4r -v '1.2.1' --source 'https://rubygems.org/' -- --with-cflags="-Wno-error=implicit-function-declaration -Wno-error=incompatible-function-pointer-types"