On a laptop that I've just rebuilt recently, I created and have been using an ED25519 SSH key pair, including with Github. Iceberg doesn't work with it though, throwing the error 'LGit_GIT_ERROR: No ssh-agent suitable credentials found". This is because Iceberg uses libgit2, which uses libssh2, which apparently doesn't support ED25519 keys. Created a new RSA key pair, registered it with Github, and Iceberg works.

• OS = Linux Mint 18.1
• Pharo image = 60510-64
• Pharo VM = pulled from GH opensmalltalk-vm today and built on said laptop