Ludovic Courtès writes:

> Out of curiosity, what package was this?

I encountered it first in jison, a javascript parser generator.

> Since this is a rebuild-the-world change, I applied to to a new
> ‘core-updates’ branch (and adjusted the commit log.)

Yes, I got bitten by that, trying to test it.  I had an interesting
learning experience getting to know guix and getting this to work and
reverted to using

    (#phases
     (replace 'patch-source-shebangs
              ;;patch-source-shebangs-no-symlinks
              (lambda* (#:key outputs #:allow-other-keys)
                (for-each patch-shebang
                          (remove (lambda (file)
                                    (or (not (file-exists? file)) ;dangling symlink
                                        ;;(file-is-symlink? file)
                                        (and (file-exists? file)
                                             (eq? 'symlink (stat:type (lstat file))))
                                        (file-is-directory? file)))
                                  (find-files ".")))))

in the package itself.  Rebuilding the world is no fun when you want to
get things done.

When I actually got to test it, it appears that something like the above
is still necessary.  It seems that the previous patch merely avoids
visiting any symlinked directories, while this version actually looks
at the script to be patched.

Greetings, Jan