Hello,

to reproduce this weird (and very specific!) problem, do the following:
   cd /tmp
   mkdir proj
copy the attached example.scm into /tmp/proj

Now
   guix refresh -u -L proj python-numpy-illustrated
yields the error
proj/example.scm:10:2: python-numpy-illustrated: updating from version 0.3 to version 0.3.1...
proj/example.scm:10:2: warning: python-numpy-illustrated: no `version' field in source; skipping
and does not update the package; whereas
   guix refresh -u -L /tmp/proj python-numpy-illustrated
works as expected.

Without the "-u" things work with a relative path (as indicated by the
first line before the error message above), and I have not found other
guix commands that pose problems with relative paths.

Andreas