>>18
I'm also having weird issues with Geiser but I don't see any problems with your example. Evaluating the second line with C-x C-e echoes:
=>new-environment
Using Emacs 27.1 with this minimal configuration for Scheme and Geiser:
;;;Scheme
(setq auto-mode-alist
(cons '("\\.scm$" . scheme-mode)
auto-mode-alist))
(load-file "~/.emacs.d/elpa/geiser-0.12/geiser.el")
(add-hook 'scheme-mode-hook 'geiser-mode)
(setq geiser-default-implementation 'mit)
(setq geiser-active-implementations '(mit))