We needed puttygen running on an Amazon Linux (Fedora) install that has a broken putty package on yum.
It fails to install because of missing X dependencies.
Honestly, I was a bit glad that it failed or it would have installed a bunch of undesired X dependencies.
Debian based distros have the advantage of having a separate package for the cli tools called putty-tools.
So if you are on Debain/Ubuntu/Mint/etc you can just
sudo apt-get install putty-tools