Can't get some emacs-guix commands to work: (list all services, sometimes list all packages)

Hi -- I've been having problems with emacs-guix for a while. I've tried the package in guix, and just tried the latest build from this repo (0.5.2-0b8f7512).

My symptoms are that when I try (from the M-x guix interface) and choose services and all:

guix-geiser-eval: Error in evaluating guile expression: ice-9/boot-9.scm:1669:16: In procedure raise-exception: error: service-sexps: unbound variable

Also, when using M-X guix for the first time, and choosing packages and all, I get:

guix-geiser-eval: Error in evaluating guile expression: ice-9/boot-9.scm:1669:16: In procedure raise-exception: Throw to key match-error' with args ("match" "no matching pattern" (unbound-variable "resolve-interface" "no binding `~A' in module ~A" (python (gnu packages python)) #f))'.

Though this seems to work if I try it again (i.e. without restarting the REPL). It thinks a lot of the packages are "unknown" though -- i.e. it cannot find them among guix's definitions.

Happy to poke at this some more. I'm a fan of your package!

(To corroborate a little, others on IRC seem to be having similar problems: http://logs.guix.gnu.org/guix/2020-05-11.log#035718 )