Nigko, that you attempted the recipe and found an error and a fix is
extremely helpful.  It seems to me that what is written in "The
Repository as a Channel", when copied literally, has never worked.

I tried with a guile package instead of your test-repo package,
using gnu-build-system rather than copy-build-system, and both
current guix master branch as well as old version-1.4.0 branch.
It still failed, like you wrote.

I turned your description of the work-around into a patch,
(see e-mail attachment), in your name and e-mail address, with
copyright.

Your work-around is to move the package, for which guix.scm is a
symlink, to its own directory.  It works for me.  And looks like a
good recommendation in general.

I believe Attila Lendvai’s bug with (current-filename) being #f
will *not* lead to a fix that makes this cookbook change unnecessary.

Is the patch okay?  Do you have suggestions for a better commit message?
May I push it to the guix repo?

Regards,
Florian