Adding general tips of how to troubleshoot the instalation of single user nix installer

[PedroRegisPOAR]

TODO:

• https://nixos.wiki/wiki/Nix_Installation_Guide

Checking environment variables

env
env | grep 'some_env_var name'

declare -px > env.sh
source env.sh

https://stackoverflow.com/a/39119103

The /tmp thing

The ~/tmp and/or /tmp:

• No space left on device when using docker-compose, why ?

• This means either /tmp, /run/user/$UID or your TMPFS runs full. sometimes setting TMPDIR to some other location can help, sometimes /tmp needs to be on a bigger partition (not a tmpfs).
  https://github.com/nix-community/nixos-generators/tree/cf341a2c94338eed91c35df291931ea775b31e99#no-space-left-on-device

• TMPDIR handling by nix-shell NixOS/nix#395 (comment)

• TMPDIR handling by nix-shell NixOS/nix#395 (comment)

• nix develop: use proper permissions for $TMPDIR NixOS/nix#6974 (comment)

• About xattrs in the DeterminateSystems . I think the tmpfs, in some situations does not have this xattrs thing.

security_model=mapped-xattr

Refs.:

• https://wiki.qemu.org/Documentation/9psetup#Starting_the_Guest_directly

## FIX for running out of space / tmp, which is used for building
fileSystems."/nix/.rw-store" = {
  fsType = "tmpfs";
  # options = [ "mode=0755" ];
  options = [ "mode=0755" "nosuid" "nodev" "relatime" "size=14G" ];
  neededForBoot = true;
};

From: https://githubmemory.com/repo/colemickens/nixcfg/issues/3

Remote builders

{ nix.trustedUsers = [ "@wheel" ]; } # or specific user

• nixos-rebuild with remote target fails due to lack of valid signature NixOS/nixpkgs#159082 (comment)

[PedroRegisPOAR]

Using the CLI

nix flake update --override-input nixpkgs nixpkgs/84aa23742f6c72501f9cc209f29c438766f5352d

nix \
flake \
update \
--override-input nixpkgs github:NixOS/nixpkgs/nixos-21.11

[PedroRegisPOAR]

TODO: take a look in that.

However, if nix has to build a derivation, it has to spin up a builder... And builders run in a user namespace with uids and gids mapped and significantly less permissions. That builder is what's spitting out that error.
From: NixOS/nixpkgs#67465 (comment)

[PedroRegisPOAR]

TODO:

• https://github.com/nix-community/nix-installers/tree/93907b1b4a34b4391bc3e776a410213669f64074

$ nix build github:nix-community/nix-installers/93907b1b4a34b4391bc3e776a410213669f64074#deb
$ ls -al result 
lrwxrwxrwx 1 pedro pedro 68 jul  6 13:04 result -> /nix/store/a6li3c1in0cia6a4nsmy4nnvh3b550hq-nix-multi-user-2.9.1.deb