bug#52702: Cannot install a package from a `nar' archive without network access.

[Pierre-Henry Fröhring]

Hello,

I cannot get Guix to install a package from a `nar' archive without network 
access. 
Here are the steps to reproduce the unexpected behaviour : 

These commands :


┌────
│ guix install hello
│ guix archive --export -r hello > hello.nar
│ guix remove hello
│ guix package --delete-generations
│ guix gc
│ guix archive --import < ./hello.nar
│ guix package -i /gnu/store/81bdcd5x4v50i28h98bfkvvkx9cky63w-hello-2.10
└────

give :

┌────
│ Le paquet suivant sera installé :
│    hello 2.10
│ 
│ La dérivation suivante sera compilée :
│    /gnu/store/b3zshi8adni3xy2zn3cngayh5dhfvvrs-profile.drv
│ 
│ 32,0 Mo seront téléchargés
│ guix substitute: error: erreur lors de la consultation du nom d'h\u00f4te : 
Nom ou service inconnu
│ la substitution de 
/gnu/store/gzh4pjhzhbfbn4kdiba3hl8b264y19q4-module-import-compiled a échoué
│ guix package: erreur : some substitutes for the outputs of derivation
│ `/gnu/store/6i7mhz4vxl4g19q7cabc0rvmpw5dijzx-module-import-compiled.drv' 
failed
│ (usually happens due to networking issues); try `--fallback' to build 
derivation from
│ source
└────