Guile 2.0.11 error during test of package definition on Trisquel 7

[swedebugia@riseup.net]

Hi

I tried following the manual build* from a fresh git pull.

 From 7.6:
"   ./pre-inst-env guix build gnew --keep-failed
    If the package is unknown to the ‘guix’ command, it may be that the
source file contains a syntax error, or lacks a ‘define-public’ clause
to export the package variable.  To figure it out, you may load the
module from Guile to get more information about the actual error:

      ./pre-inst-env guile -c '(use-modules (gnu packages gnew))'"

After putting the new package definition below into python.scm:
(define-public python-twisted
   (package
     (name "python-twisted")
     (version "15.5.0")
     (source
      (origin
        (method url-fetch)
;       (extension "tar.bz2")
;       (uri (pypi-uri "Twisted" version extension))
        (uri (pypi-uri "Twisted" version))
        (sha256
         (base32
          "0zy18lcrris4aaslil5k12i13k56c32hzfdv6h10kbnzl026h158"))))
     (build-system python-build-system)
     (inputs
      `(("python-setuptools" ,python-setuptools)))
     (home-page "http://twistedmatrix.com/")
     (synopsis
      "An asynchronous networking framework written in Python")
     (description
      "An asynchronous networking framework written in Python")
     (license license:expat)))

./pre-inst-env guix build cannot find it.
I then do:
$ ./pre-inst-env guile -c '(use-modules (gnu packages python))'
but it tries to auto-compile python.scm and fails with:
;;; ERROR: failed to create path for auto-compiled file "path/to/file"

WTF?

 From within guix environment guix --container:
it compiles without errors.

cheers
swedebugia