Hi!

Is it possible to export a .nar including the sources necessary to 
rebuild that package?

I tried running these commands on the host:

sudo guix archive --generate-key
guix archive --export --recursive hello > hello.nar

And these commands inside a fresh, minimal GUIX environment without 
network access:

guix archive --authorize < signing-key.pub
guix archive --import < hello.nar
$(guix build hello)/bin/hello # works
guix build --check hello # fails

The above fails because it tries to download the sources:

Starting download of /gnu/store/…-hello-2.10.tar.gz
 From https://gtpmirror.gnu.or/gnu/hello/hello-2.10.tar.gz...
In procedure getaddringo: Name or service not known

I have created at 
https://github.com/jsmaniac/guix-reproducible-system/tree/guix-question 
a small automated environment which creates the archive, creates a QEMU 
VM with a minimalistic Guix configuration, copies the .nar archive 
inside the VM and tries the commands above.

Thanks,
Georges Dupéron