Also it seems that the texlive importer is broken:

--8<---------------cut here---------------start------------->8---
> guix import texlive fontspec
following redirection to `https://ctan.org/xml/1.2/pkg/fontspec'...
Backtrace:
          10 (apply-smob/1 #<catch-closure 246c040>)
In ice-9/boot-9.scm:
    705:2  9 (call-with-prompt _ _ #<procedure default-prompt-handler (k proc)>)
In ice-9/eval.scm:
    619:8  8 (_ #(#(#<directory (guile-user) 250a140>)))
In guix/ui.scm:
  1535:12  7 (run-guix-command _ . _)
In guix/scripts/import.scm:
   114:11  6 (guix-import . _)
In guix/scripts/import/texlive.scm:
    91:19  5 (guix-import-texlive . _)
In guix/memoization.scm:
     98:0  4 (_ #<hash-table 2a29620 0/31> ("fontspec" "latex") _)
In unknown file:
           3 (_ #<procedure 2695d00 at guix/memoization.scm:179:32 ()> #<procedure list _> #)
In guix/import/texlive.scm:
   157:25  2 (sxml->package (*TOP* (entry (@ (id "fontspec")) (name "fontspec") (# #) …)) _)
In guix/serialization.scm:
   270:25  1 (write-file #f #<output: string 27e0700> #:select? _)
In unknown file:
           0 (lstat #f)

ERROR: In procedure lstat:
Wrong type (expecting string): #
--8<---------------cut here---------------end--------------->8---

-- 
Peter Neidhardt

"How to make a million dollars:  First, get a million dollars."
-- Steve Martin