1) I would guess that guix environment emacs, looks in the package definition to discover emacs' dependencies.
2) Are you trying to create a custom emacs package? If so, then you might like my jmacs package: https://notabug.org/jbranso/guix-packages/src/master/packages/jmacs.scm 3) I would guess "guix build <package name>". You could have a custom channel that is local to your machine. Any packages in it, take precedent over packages in guix proper. That is to say, that your custom emacs package named "emacs" and is available locally, would be built instead of the "emacs" package in guix. You could also define I personally do this in my ~/.bash_profile #+BEGIN_SRC sh export GUIX_PACKAGE_PATH=/home/joshua/prog/gnu/guix/guix-packages/ #+END_SRC -- Joshua Branson Sent from Emacs and Gnus