Alex Kost <alezost@gmail.com> writes:

> and I would make it more robust: there is a
> problem with this code: (string-drop "geiser" 6) does not return what
> you mean

Yes, because "geiser" differs from most of Emacs packages:

    ls /gnu/store/7rl2k8ismmyq9ic6ha6vzv38a3hrrni2-emacs-dash-2.13.0/share/emacs/site-lisp/guix.d/dash-2.13.0/
    dash-autoloads.el  dash.el  dash.elc  dash-functional.el  dash-functional.elc

    ls /gnu/store/7lh77fmapmjjv3kj2q69dy58kjniw9am-geiser-0.9/share/emacs/site-lisp/
    geiser-autodoc.el    geiser-chibi.elc	…

Maybe we just need to fix "geiser"?

> , and (string-drop "dash" 6) errors!

Do you really mean emacs-dash or dash?  For me both succeeded.

As I see emacs-dash is OK, except "emacs-minimal" in EMACSLOADPATH.
Here is a log-file with DEBUG-INPUTS: