"nix-channel --update" fails -- "warning: the group 'nixbld' specified in 'build-users-group' does not exist"

[drewboardman]

OS: Arch Linux 5.4.15-arch1-1
Nix Version: nix (Nix) 2.3.1

Steps taken

• Installed nix using the single user/unprivileged instructions in the arch wiki.

$ yay -S nix
$ sudo chown -R $USER. /nix/var/nix/{gcroots,profiles.db}
$ nix-channel --add https://nixos.org/channels/nixpkgs-unstable

$ nix-channel --list
nixpkgs https://nixos.org/channels/nixpkgs-unstable

$ nix-channel --update
unpacking channels...
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
while setting up the build environment: executing '/usr/bin/bash': No such file or directory
builder for '/nix/store/083z09myxrv7dlj6py6x1sbdvf2b7mg2-nixpkgs-20.03pre210643.ec1c46e2e58.drv' failed with exit code 1
error: build of '/nix/store/083z09myxrv7dlj6py6x1sbdvf2b7mg2-nixpkgs-20.03pre210643.ec1c46e2e58.drv' failed
error: program '/usr/bin/nix-env' failed with exit code 100

After this, I tried with sudo (also described in the arch wiki):

$ sudo nix-channel --update
warning: the group 'nixbld' specified in 'build-users-group' does not exist
unpacking channels...
warning: the group 'nixbld' specified in 'build-users-group' does not exist
error: the group 'nixbld' specified in 'build-users-group' does not exist
error: program '/usr/bin/nix-env' failed with exit code 1

• So, the two errors are saying:

• no-sudo: my channel path doesn't exist
• sudo: there is a group that doesn't exist

Checking on channel path

• I want to make sure that its looking in the correct place, and that I have permissions:

$ echo $NIX_PATH
nixpkgs=/nix/var/nix/profiles/per-user/root/channels/nixpkgs:
              /nix/var/nix/profiles/per-user/root/channels:
              /home/drew/.nix-defexpr/channels

# now I want to check what's in that home dir

$ ll ~/.nix-defexpr
total 8.0K
lrwxrwxrwx  1 drew users   44 Jan 21 17:32 channels_root -> /nix/var/nix/profiles/per-user/root/channels
lrwxrwxrwx  1 drew users   44 Jan 22 11:29 channels -> /nix/var/nix/profiles/per-user/drew/channels/
drwxr-xr-x  2 drew users 4.0K Jan 22 11:29 ./
drwx------ 35 drew users 4.0K Jan 27 16:45 ../

# checking to make sure I have permissions on those dirs

$ sudo ls -alh /nix/var/nix/profiles/per-user
total 16K
drwxr-xr-x 4 drew users 4.0K Jan 27 16:22 .
drwxr-xr-x 3 drew users 4.0K Jan 21 17:32 ..
drwxr-xr-x 2 drew users 4.0K Jan 27 16:09 drew
drwxr-xr-x 2 root root  4.0K Jan 27 16:22 root

# now I can see that those dirs don't exist (this seems to be an issue)

$ sudo ls -alh /nix/var/nix/profiles/per-user/root
total 8.0K
drwxr-xr-x 2 root root  4.0K Jan 27 16:22 .
drwxr-xr-x 4 drew users 4.0K Jan 27 16:22 ..

Attempted solution

• Make that channels dir and try to update

• fails

$ sudo mkdir /nix/var/nix/profiles/per-user/root/channels
$ sudo nix-channel --update
warning: the group 'nixbld' specified in 'build-users-group' does not exist
unpacking channels...
warning: the group 'nixbld' specified in 'build-users-group' does not exist
error: '/nix/var/nix/profiles/per-user/root/channels' is not a symlink
error: program '/usr/bin/nix-env' failed with exit code 1

$ nix-channel --update                                                                                                                                                       
unpacking channels...
while setting up the build environment: executing '/usr/bin/bash': No such file or directory
builder for '/nix/store/083z09myxrv7dlj6py6x1sbdvf2b7mg2-nixpkgs-20.03pre210643.ec1c46e2e58.drv' failed with exit code 1
error: build of '/nix/store/083z09myxrv7dlj6py6x1sbdvf2b7mg2-nixpkgs-20.03pre210643.ec1c46e2e58.drv' failed
error: program '/usr/bin/nix-env' failed with exit code 100

[drewboardman]

Some info:

From the aur entry for nix I attempted to change the nix config sandbox mode to false.

$ cat ~/.config/nix/nix.conf
sandbox = false
substituters = https://cache.nixos.org https://all-hies.cachix.org
trusted-public-keys = cache.nixos.org-1:6NCHdD59X431o0gWypbMrAURkbJ16ZPMQFGspcDShjY= all-hies.cachix.org-1:JjrzAOEUsD9ZMt8fdFbzo3jNAyEWlPAwdVuHw4RD43k=

This allowed me to update channels without error (I think).

$ nix-channel --update
unpacking channels...
warning: Nix search path entry '/nix/var/nix/profiles/per-user/root/channels' does not exist, ignoring
created 1 symlinks in user environment

[makefu]

for anyone who is interested, these were the steps i needed to install the latest nix (2.3.1), from AUR, on a fresh archlinux docker container:

$ docker run -ti archlinux
pacman --noconfirm -Sy base-devel
curl https://aur.archlinux.org/cgit/aur.git/snapshot/editline.tar.gz | tar xz && cd editline/
env EUID=1 makepkg -si --noconfirm  # hack to run makepkg as root
curl https://aur.archlinux.org/cgit/aur.git/snapshot/nix.tar.gz | tar xz && cd nix/
pacman --noconfirm -S libsodium boost brotli
env EUID=1 makepkg -si --noconfirm
useradd nixbld
gpasswd -a nixbld nixbld
nix-channel --add https://nixos.org/channels/nixpkgs-unstable
nix-channel --update
NIX_PATH=/nix/var/nix/profiles/per-user/root/channels nix-shell -p python3

[veprbl]

This issue belongs to NixOS/nix repository and not NixOS/nixpkgs

[drewboardman]

This issue belongs to NixOS/nix repository and not NixOS/nixpkgs

The NixOS/nix issue placeholder text recommends posting in this issue board.

[stevenroose]

Did you get this to work? I'm also failing to update my nix system to unstable.

I think what you needed was archlinux-nix setup-build-group perhaps. (archlinux-nix is in AUR; see Arch wiki's page for nix)

[stale]

I marked this as stale due to inactivity. → More info