Thomas Eckert's Dotfiles

This repository helps me unify development environments between multiple MacOS systems. It contains configuration files for applications I use and small sharp tools I've written to make my work more effective.

Installation

Clone the repository and run ./install.sh:

./install.sh

This will:

1. Install Nix via Determinate Systems installer
2. Configure your user as a trusted user (no more sudo for nix commands!)
3. Set up nix-darwin for macOS system configuration
4. Apply Home Manager for user environment

Homebrew is not a separate step: nix-homebrew installs and owns /opt/homebrew during activation, at the version pinned in flake.nix. An existing Homebrew installation is adopted automatically (autoMigrate).

After installation, apply the full configuration:

# First time: Bootstrap nix-darwin
nix run nix-darwin -- switch --flake .

# Subsequent updates (activation must run as root):
sudo darwin-rebuild switch --flake .
# Or use the alias: reload-nix

Adding a new machine

darwin-rebuild --flake . resolves darwinConfigurations.$(hostname -s). macOS picks that hostname from the account's full name during setup, so it is not consistent between machines — one Mac is Thomas-MacBook-Pro, another is Thomass-MacBook-Pro.

To onboard a new Mac:

# 1. Activate without caring about the hostname
task bootstrap          # activation runs as root; the task handles the sudo

# 2. Add the machine's name to `darwinHosts` in flake.nix
task hosts              # shows this machine's name and the configured ones

# 3. From then on, the bare form works
task rebuild            # or: sudo darwin-rebuild switch --flake .

Each listed hostname pins itself via networking.hostName in nix/darwin, so once a machine has switched, its name and the flake cannot drift apart.

Troubleshooting

Error: An existing /opt/homebrew/Library/Taps is in the way

Hit when migrating a machine that already had Homebrew installed by the official script. nix-homebrew.autoMigrate deletes the Homebrew repository but never touches Library/Taps, and mutableTaps = false needs to replace that directory with a symlink into the store. Move it aside and re-run:

mv /opt/homebrew/Library/Taps ~/homebrew-taps-pre-nix
task rebuild

Nothing is lost -- the taps are supplied by the flake inputs. Note that on Apple Silicon the prefix is the repository, so a failure here leaves /opt/homebrew/bin/brew deleted and Homebrew unusable until the rebuild completes. Installed formulae and casks under Cellar/Caskroom are not affected.

Upgrading Homebrew

Homebrew's version is pinned by the brew-src input in flake.nix. To move to a new release, bump the tag and rebuild:

# edit flake.nix:  url = "github:Homebrew/brew/<new-tag>";
nix flake update brew-src
task rebuild
brew --version   # should report <new-tag>

brew update cannot move Homebrew off the pin -- nix-homebrew patches the self-update path out of cmd/update.sh and exports HOMEBREW_NO_AUTO_UPDATE=1. Taps are pinned the same way, as flake inputs; because mutableTaps = false, brew tap no longer works imperatively and adding a tap means editing nix/darwin/default.nix and rebuilding.

error: flake ... does not provide attribute 'darwinConfigurations.<name>.system'

The machine's hostname is not in darwinHosts. Either activate explicitly with an existing config:

nix run nix-darwin -- switch --flake .#default

or add the hostname to darwinHosts in flake.nix and switch normally.

If nix commands require sudo:

The installer automatically configures trusted users, but if you need to do it manually:

# Add yourself to trusted users
sudo tee -a /etc/nix/nix.custom.conf > /dev/null <<EOF

# Allow user to run nix commands without sudo
trusted-users = root $(whoami)
EOF

# Restart the nix daemon
sudo launchctl kickstart -k system/systems.determinate.nix-daemon

# Verify you're trusted
nix store ping  # Should show "Trusted: 1"

Configs

• Atuin
• GitHub CLI
• Ghostty
• Helm
• K9s
• Neovim
• Zellij

Tools

I've unified my tooling around simple Go applications. They are all available in tools. The install script

• create-react-component generates a new React component with the given name.
• fetch-gitignore fetches a .gitignore file from the GitHub gitignore repository.
• normalize-lines normalizes lines in a string of text to be 80 characters long without breaking words.
• prepend a file renaming tool which will prepend a given string to a glob.
• serve serve the current directory as a file server.
• slug
• teamtime tells you what time is is for everyone on your team.