Hi,

"guix package -L /path/to/pkgs" command does not add "/path/to/pkgs" into "(%patch-path)". 

In same time command "GUIX_PACKAGE_PATH=/path/to/pkgs guix package" works fine.

I checked this behaviour on https://github.com/mnd/guix-mnd-pkgs repository.
Regards,
Nikolay