Guix doesnt use guix publish as a substitute

[edk@beaver-labs.com]

Dear Guixers,

On one machine I have the following:
$guix describe
guile: warning: failed to install locale
Génération 2    01 sept. 2020 17:10:25  (actuelle)
  beaverlabs d878892
    URL du dépôt : https://gitlab.com/edouardklein/guix
    branche: beaverlabs
    commit : d8788927c7e8b29702adb971bf1ffbc3235fba22
  guix 6bf5f20
    URL du dépôt : https://git.savannah.gnu.org/git/guix.git
    branche: master
    commit : 6bf5f207f171e87a53e6578a61b4334683a861c8

On another I have:

$guix describe
Generation 4    Sep 01 2020 17:32:39    (current)
  beaverlabs d878892
    repository URL: https://gitlab.com/edouardklein/guix
    branch: master
    commit: d8788927c7e8b29702adb971bf1ffbc3235fba22
  guix 6bf5f20
    repository URL: https://git.savannah.gnu.org/git/guix.git
    branch: master
    commit: 6bf5f207f171e87a53e6578a61b4334683a861c8

I then run guix build gerbil on the first machine, then  guix publish, and make it available to
the second using a ssh tunnel and run

guix build --substitute-urls=http://localhost:8080 --dry-run gerbil

on the second machine, and I get:

substitute: /gnu/store/29jhbbg1hf557x8j53f9sxd9imlmf02a-bash-minimal-5.0.7/bin/bash: warning: setlocale: LC_ALL: cannot change locale (en_US.utf8)
The following derivation would be built:
   /gnu/store/0nl1kmsqnbba4z47p28y0n023kbnvl8w-gerbil-0.16.drv


My question is: why isn't the second machine fetching a binary package
of gerbil from the first ? Why does it try to build it (it can't, not
enough RAM) ?

I have no idea how to debug this.

I tried curling http://localhost:8080 on the second machine, which gives
me the nice "Guix publish speaking" message.

I noticed that on the second machine, it believes that commit d878892 is
on branch master, which it isn't, it's on branch beaverlabs, but I don't
think this matters, does it ?


Any help would be appreciated.

Thanks,

Edouard.