bug#45656: The TeX Live importer crashes with Wrong type (expecting string): #f

[Maxim Cournoyer <maxim.cournoyer@gmail.com>]

Hello,

The TeX Live importer doesn't appear to be functional:

$ guix import texlive lh
following redirection to `https://ctan.org/xml/1.2/pkg/lh'...
command "svn" "export" "--non-interactive" "--trust-server-cert" "-r" "51265" "svn://www.tug.org/texlive/tags/texlive-2019.3/Master/texmf-dist/source/latex/lh" "/tmp/guix-directory.vfSCcU/svn" failed with signal 11
Backtrace:
In ice-9/boot-9.scm:
  1736:10 15 (with-exception-handler _ _ #:unwind? _ #:unwind-for-type _)
In unknown file:
          14 (apply-smob/0 #<thunk 7fb1a712a4a0>)
In ice-9/boot-9.scm:
    718:2 13 (call-with-prompt _ _ #<procedure default-prompt-handler (k proc)>)
In ice-9/eval.scm:
    619:8 12 (_ #(#(#<directory (guile-user) 7fb1a6d67f00>)))
In guix/ui.scm:
  2118:12 11 (run-guix-command _ . _)
In guix/scripts/import.scm:
   120:11 10 (guix-import . _)
In guix/scripts/import/texlive.scm:
    91:19  9 (guix-import-texlive . _)
In guix/memoization.scm:
     98:0  8 (mproc "lh" "latex")
In unknown file:
           7 (_ #<procedure 7fb1a4c85a20 at guix/memoization.scm:179:32 ()> #<procedure list _> ("lh" …))
In ice-9/boot-9.scm:
  1736:10  6 (with-exception-handler _ _ #:unwind? _ #:unwind-for-type _)
In guix/store.scm:
   632:37  5 (thunk)
In guix/import/texlive.scm:
   162:25  4 (_ _)
In guix/serialization.scm:
    324:6  3 (dump #f)
   257:34  2 (_ _)
In unknown file:
           1 (lstat #f)
In ice-9/boot-9.scm:
  1669:16  0 (raise-exception _ #:continuable? _)

ice-9/boot-9.scm:1669:16: In procedure raise-exception:
Wrong type (expecting string): #f

The same happens with other packages, such as 'ec'.

Thanks,

Maxim