Troubleshooting Ruby 2.7 compiler errors

So Ruby 2.7 was released at Xmas'19 and I got some errors when compiling it in Linux Mint 19.1. Some libraries were not configured. The errors ocurred at the linking phase of make. Five libraries got errors, and I'll walk across their solutions:

• openssl:
  sudo apt install libssl-dev
• gdbm:
  sudo apt install libgdbm-dev
• dbm:
  sudo apt install libqdbm-dev
• readline:
  sudo apt install libedit-dev
• zlib:
  sudo apt install libz-dev
cd /lib/x86_64-linux-gnu/
sudo ln -s libz.so.1 liblibz.so

Enjoy!

Detecting key press in Ruby

To check whether a key is pressed in linux (non-blocking, non-waiting).

def keypressed
  system('stty raw -echo') # => Raw mode, no echo
  char = (STDIN.read_nonblock(1).chr rescue nil)
  system('stty -raw echo') # => Reset terminal mode
  char
end

Inspired on https://stackoverflow.com/a/22659929.