OS-X, Rails: “Failed to build gem native extension”

Question

I\'m stuck trying to install rails on my mac. I have OS X 10.6.8 and I have confirmed that I have Ruby, version 1.8.7

I ran sudo gem update and su

Answer 1

https://stackoverflow.com/a/58226876/8070378

Solved after run:

sudo xcode-select --install
sudo xcodebuild -license accept