> See ‘package-from-tarball’ for an example, in bootstrap.scm.

Thanks.  Can I push the attached patch along with this one [1,2]?

Two questions, though:

1. Is it necessary to use 'begin' here?

(begin
  (mkdir out)
  (copy-file tarball "grue-hunter.tar.gz")
  ...)

2. I'd like to use

(patch-shebang (string-append bin "/grue-hunter")
			   (list perl))

instead of

(substitute* (string-append bin "/grue-hunter")
  (("#!/usr/bin/perl") (string-append "#!" perl)))

But the former fails to find Perl.  Why?

[1] https://lists.gnu.org/archive/html/bug-guix/2013-05/txtJNCpY2SXeq.txt
[2] https://lists.gnu.org/archive/html/bug-guix/2013-05/msg00036.html