bug#42173: Nix on Guix System: can't update channels

[Alexandru-Sergiu Marton <brown121407@posteo.ro>]

Hi,

I tried to set up the Nix package manager on my Guix System 
following the instructions at 
http://guix.gnu.org/manual/en/guix.html#index-Nix . 
Unfortunately, after reconfiguring the system and adding a channel 
with `nix-channel --add 
https://nixos.org/channels/nixpkgs-unstable`, when I tried to 
update the channels (`nix-channel --update`), this is what I got:

--8<---------------cut here---------------start------------->8--- 
[brown@121408 ~]$ nix-channel --update unpacking channels... 
while setting up the build environment: executing 
'/gnu/store/pwcp239kjf7lnj5i4lkdzcfcxwcfyk72-bash-minimal-5.0.16/bin/bash': 
No such file or directory builder for 
'/nix/store/fqvvrsyznxfzckxbiz6krlykdb6w105n-nixpkgs-20.09pre232864.55668eb671b.drv' 
failed with exit code 1 error: build of 
'/nix/store/fqvvrsyznxfzckxbiz6krlykdb6w105n-nixpkgs-20.09pre232864.55668eb671b.drv' 
failed error: program 
'/gnu/store/lsixql26nig4v3icn124ja3ivjpgvn99-nix-2.3.6/bin/nix-env' 
failed with exit code 100 --8<---------------cut 
here---------------end--------------->8--- 

Any tips on how to fix this?

Cheers,
Sergiu