That M-. doesn't work doesn't necessarily mean that the .scm file is not an geiser-mode. If the mode line says something like "(Scheme Guile/A)", it's active. M-. might fail to find a symbol simply because the module is not loaded in the interpreter (e.g. with C-cC-k), but it's hard to tell without knowing more about what you mean with "it doesn't work".
Cheers, jao -- Besides the noble art of getting things done, there is the noble art of leaving things undone. The wisdom of life consists in the elimination of nonessentials. -Lin Yutang, writer and translator (1895-1976)
