ark@ark ~$ guix import gnu tuxkart
Backtrace:
          10 (primitive-load "/home/ark/.config/guix/current/bin/guix")
In guix/ui.scm:
  2127:12  9 (run-guix-command _ . _)
In guix/scripts/import.scm:
   120:11  8 (guix-import . _)
In ice-9/boot-9.scm:
  1736:10  7 (with-exception-handler _ _ #:unwind? _ # _)
  1731:15  6 (with-exception-handler #<procedure 7f6cb35dbc30 at ic…> …)
In guix/import/gnu.scm:
    111:2  5 (gnu->guix-package "tuxkart" #:key-download _)
In guix/gnu-maintenance.scm:
   364:20  4 (latest-ftp-release "tuxkart" #:server _ #:directory _ # …)
In guix/ftp-client.scm:
    233:6  3 (ftp-list #<<ftp-connection> socket: #<input-output: s…> …)
In srfi/srfi-1.scm:
   460:18  2 (fold #<procedure 7f6cb35dbb70 at guix/ftp-client.scm:…> …)
In guix/ftp-client.scm:
     74:8  1 (_ _ _)
In ice-9/boot-9.scm:
  1669:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1669:16: In procedure raise-exception:
Throw to key `ftp-error' with args `(#<input-output: socket 14> "CWD tuxkart" 550 "Failed to change directory.\r")'.