nix-config

Personal nix-config.

Current state: nixos, nix-darwin and standalone home-manager.

Development

Build custom package:

nix build .#PACKAGE

Adding a host

1. Add the host configuration to hosts/{HOST_NAME}/default.nix. Modify home.nix and host.nix as needed.
2. Generate the host keys, add the public key to your secrets, and re-encrypt the secrets.
3. Add the new host configuration to hosts/default.nix.
4. Deploy the configuration to your host.
   • If you're adding a new host with a standalone Home Manager setup, using nix develop might be helpful.

Raspberry Pi: Build and Flash an SD Card Image

We use raspberry-pi-nix for Raspberry Pi setup. Make sure to check the documentation first.

Building an image and flashing it to an SD card is an effective way to set up your Raspberry Pi:

nix build '.#nixosConfigurations.rpi-example.config.system.build.sdImage'
zstdcat result/sd-image/nixos-sd-image-23.11.20230703.ea4c80b-aarch64-linux.img.zst \
    | sudo dd of=/dev/mmcblk0 bs=100M

This method creates and deploys a ready-to-use NixOS image to your SD card.

Known issues

Darwin apps in dock

To remove the uninstalled APPs icon from Launchpad:

1. sudo nix store gc --debug && sudo nix-collect-garbage --delete-old
2. click on the uninstalled APP's icon in Launchpad, it will show a question mark
3. if the app starts normally:
   1. right click on the running app's icon in Dock, select "Options" -> "Show in Finder" and delete it
4. hold down the Option key, a x button will appear on the icon, click it to remove the icon

Agenix

Debug activation on darwin

launchd.daemons.activate-agenix.serviceConfig = {
  StandardOutPath = "/var/log/activate-agenix.out";
  StandardErrorPath = "/var/log/activate-agenix.err";
};

Home Manager

Each time when you add/edit/delete home secrets, you will have to run the following script manually:

systemctl --user start agenix.service

This is a bug with agenix.

Proxy

Setup proxy with systemd override (especially useful for non-nixos)

# https://github.com/NixOS/nixpkgs/issues/27535#issuecomment-1178444327
# equals: sudo systemctl edit --runtime nix-daemon
sudo mkdir /run/systemd/system/nix-daemon.service.d/
cat << EOF >/run/systemd/system/nix-daemon.service.d/override.conf
[Service]
Environment="http_proxy=socks5h://localhost:7891"
Environment="https_proxy=socks5h://localhost:7891"
Environment="all_proxy=socks5h://localhost:7891"
EOF
sudo systemctl daemon-reload
sudo systemctl restart nix-daemon

Proxy may be a problem when your proxy server stops to work...

sudo mount -o remount,rw /nix/store
# Look for the file and remove the lines:
sudo systemstd cat nix-daemon
sudo mount -o remount,ro /nix/store
sudo systemctl stop nix-daemon.socket nix-daemon
sudo systemctl start nix-daemon

NVIDIA Driver

After upgrading the NVIDIA driver, you may encounter:

nvidia-smi
Failed to initialize NVML: Driver/library version mismatch

To fix it, you need to reload the driver. The easiest way is rebooting. If you can't reboot, follow these steps:

1. Check which modules are loaded: lsmod | grep nvidia and find processes using NVIDIA: lsof | grep nvidia
2. Stop services if needed (e.g., stop GNOME with sudo systemctl isolate multi-user.target)
3. Unload modules: sudo modprobe -r nvidia_uvm nvidia_drm nvidia_modeset nvidia. If modprobe -r fails, check what is still using the modules and kill the processes manually.
4. Reload module: sudo modprobe nvidia
5. Test again: nvidia-smi. If problems persist, a full system reboot is recommended.