I'm newbie to Guix and know little about Guix jargon. I'm sorry about that my words make you puzzled.
>? The source of what?
I mean the emacs package in guix source, the emacs-next package, precisely.
>> will record its modification of EMACSLOADPATH in profile,
>
>Where is it recorded? Which modification? What is "EMACSLOADPATH in profile"?
The package definition of emacs-next has native-search-path field, which add customized EMACSLOADPATH environment variable.
And I guess it modified ~/.guix-profile/etc/profile.
If you still doesn't understand, please ask me again, thanks!