pyrox.dev
lol
nix-channel: do not set empty nix-path when disabling channels
An empty nix-path in nix.conf will disable NIX_PATH environment variable
entirely, which is not necessarily implied by users who want to disable
nix channels. NIX_PATH also has some usages in tools like nixos-rebuild
or just as user aliases.
That change is surprising and debatable, and also caused breakages in
nixpkgs-review and user configs.
See:
- https://github.com/NixOS/nixpkgs/pull/242098/files#r1269891427
- https://github.com/Mic92/nixpkgs-review/issues/343
- https://github.com/NixOS/nix/pull/10998
Co-authored-by: oxalica <oxalicc@pm.me>
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-2
+22
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nixos/modules/config/nix-channel.nix
+22
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nixos/modules/config/nix-channel.nix
···
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mkDefault
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mkIf
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mkOption
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+
stringAfter
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types
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;
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···
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NIX_PATH = cfg.nixPath;
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};
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-
nix.settings.nix-path = mkIf (! cfg.channel.enable) (mkDefault "");
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-
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systemd.tmpfiles.rules = lib.mkIf cfg.channel.enable [
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''f /root/.nix-channels - - - - ${config.system.defaultChannel} nixos\n''
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];
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+
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system.activationScripts.no-nix-channel = mkIf (!cfg.channel.enable)
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(stringAfter [ "etc" "users" ] ''
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if [ -e "/root/.nix-defexpr/channels" ]; then
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echo "WARNING: /root/.nix-defexpr/channels exists, but channels have been disabled." 1>&2
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echo "Due to https://github.com/NixOS/nix/issues/9574, Nix may still use these channels when NIX_PATH is unset." 1>&2
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echo "Delete the above directory to prevent this." 1>&2
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fi
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if [ -e "/nix/var/nix/profiles/per-user/root/channels" ]; then
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echo "WARNING: /nix/var/nix/profiles/per-user/root/channels exists, but channels have been disabled." 1>&2
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echo "Due to https://github.com/NixOS/nix/issues/9574, Nix may still use these channels when NIX_PATH is unset." 1>&2
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echo "Delete the above directory to prevent this." 1>&2
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fi
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getent passwd | while IFS=: read -r _ _ _ _ _ home _ ; do
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if [ -n "$home" -a -e "$home/.nix-defexpr/channels" ]; then
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echo "WARNING: $home/.nix-defexpr/channels exists, but channels have been disabled." 1>&2
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echo "Due to https://github.com/NixOS/nix/issues/9574, Nix may still use these channels when NIX_PATH is unset." 1>&2
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echo "Delete the above directory to prevent this." 1>&2
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fi
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done
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'');
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};
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}