Hello Guix,

The attached patch fixes a regression in recursive git checkouts of
package source, which I believe was introduced in
6dff905e51202bbdebbad8811b6509584d12a796 (2017-09-05!)

This would have only affected 6 packages:

scheme@(guile-user)> (format #t "~{~a~%~}"
  (fold-packages
   (lambda (p r) 
     (if (and=> (package-source p)
                (lambda (s) 
                  (and (git-reference? (origin-uri s))
                       (git-reference-recursive? (origin-uri s))))) 
       (cons p r)
       r))
   '())
#<package brotli@0.1-1.e992cce gnu/packages/compression.scm:912 2928000>
#<package aseba@1.6.0-0.3b35de8 gnu/packages/robotics.scm:79 3199e40>
#<package cool-retro-term@1.0.1-1.dd799cf gnu/packages/terminals.scm:446 2e28b40>
#<package termite@13 gnu/packages/terminals.scm:102 2e25240>
#<package wget2@1.0.0 gnu/packages/wget.scm:126 2728900>
#<package zile-on-guile@2.4.14-0.fd09781 gnu/packages/zile.scm:83 3c660c0>
$8 = #t

`~Eric