No, this is in Emacs shell-mode on Linux (various distros over the years). Just tried a few other places: it works in qterminal, and also doesn't work in eshell

No, this is in Emacs shell-mode on Linux (various distros over the years). Just tried a few other places: it works in qterminal, and also doesn't work in eshell. I've been writing Haskell for about 15 years, including my current job as a full-time Haskell developer, and I never realised GHCi supports Ctrl-D in some situations! Every other REPL I've used handles this fine, e.g. for quitting Python, Nix repl, SSH sessions, and even the shell itself. Weird.