nix-config

My personal Nix flake for home-manager on macOS.

Install

• Install Nix package manager:

  curl -L https://nixos.org/nix/install | bash -s -- --daemon

  You can also replace the install URL with a specific version such as https://releases.nixos.org/nix/nix-2.10.3/install (this setup has been verified to work on at least 2.10.3).

• If the per-user profile directory doesn't exist for your user at /nix/var/nix/profiles/per-user/$(whoami), create it:

  sudo install -d -o $(whoami) /nix/var/nix/profiles/per-user/$(whoami)

  (install is the same as mkdir followed by chown)

• cd into this repo's directory and run the following:

  nix flake --extra-experimental-features "nix-command flakes" lock --update-input vim-plugins-overlay

• Install home-manager and activate the personal config while in this directory:

  $(
    nix build \
    --extra-experimental-features "nix-command flakes" \
    --no-link \
    --print-out-paths \
    ".#homeConfigurations.personal.activationPackage"
  )/activate

  Note that the personal config targets x86_64-darwin, so you may need to update flake.nix if on a different platform (such as aarch64-darwin).

Rebuild

After making changes to config, you can rebuild with:

home-manager switch --flake ".#personal"

To apply changes without being in this directory, replace . with the path to this directory.

Note the --extra-experimental-features flag isn't needed because our home-manager config (via the flakes module) adds the relevant lines to ~/.config/nix/nix.conf.

Updating dependencies

Dependencies are defined in flake.nix and versions are pinned in flake.lock.

• To update all dependencies:

  nix flake update

• To update a specific depedency (such as nixpkgs):

  nix flake lock --update-input nixpkgs

Errors

If you get the following error when trying to switch:

cannot fetch input 'path:./overlays/vim-plugins?...' because it uses a relative path

It's likely because changes were made to vim-plugins-overlay without updating the lock file. You may need to update it with the following command:

nix flake lock --update-input vim-plugins-overlay

Some related GitHub issues for context:

• Allow flakes to refer to other flakes by relative path
• More intelligent subflake locking.

Garbage collection

There are various levels of cleanup you can do:

# Clean up files not used by any generations of the current profile
nix-collect-garbage

# Clean up files not used by the current generation of the current profile
nix-collect-garbage -d

# Clean up files not used by the current generation for any profile
sudo nix-collect-garbage -d

Notes

In the past, it has been recommended to also run sudo mdutil -i off /nix after installation to disable spotlight indexing, but recent versions of the installer set the nobrowse option in the mount options, accomplishing the same thing. See the macOS installation section of the documentation for details.

Resources

Some resources I found useful during setup:

• home-manager config options
• Vim on NixOS
• Right way to add a custom package?
• List of configurable macOS settings
• Nix Package Versions
• Pkgs on Nix
• Flakes - NixOS Wiki
• cprussin/dotfiles
• m15a/nixpkgs-vim-extra-plugins