OS X 10.13.2 High Sierra SSH Invalid Format

OS X 10.13.2 High Sierra has broken SSH again.

$ ssh remote_server -i ~/.ssh/id_rsa.pub
$ Load key "xxx/.ssh/id_rsa.pub": invalid format

From 10.13.2 onwards the PRIVATE key is needed, earlier versions allowed the Public key “id_rsa.pub” to be used as the identity file.

So change script or ~/.ssh/config accordingly.