gistfile1.txt

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          "text": "<system-reminder>\nAs you answer the user's questions, you can use the following context:\n# claudeMd\nCodebase and user instructions are shown below. Be sure to adhere to these instructions. IMPORTANT: These instructions OVERRIDE any default behavior and you MUST follow them exactly as written.\n\nContents of /Users/johnw/src/nix/CLAUDE.md (project instructions, checked into the codebase):\n\n# CLAUDE.md\n\nThis file provides guidance to Claude Code (claude.ai/code) when working with code in this repository.\n\n## Overview\n\nThis is a personal Nix configuration repository for managing macOS (Darwin) and NixOS systems using Nix flakes, nix-darwin, and home-manager. The configuration manages three macOS hosts (hera, clio, athena) and one NixOS host (vulcan).\n\n## Working with Nix: Use Specialized Tools\n\n**IMPORTANT**: For any Nix-related tasks in this repository, you should proactively use the specialized Nix agent and tools:\n\n- **nix-pro subagent**: An expert agent specialized in NixOS, nix-darwin, home-manager, flakes, and the Nix language. Use this agent for:\n  - Modifying Nix configurations (flake.nix, darwin.nix, home.nix)\n  - Writing or debugging overlays\n  - Understanding Nix expressions and derivations\n  - Troubleshooting build failures\n  - Package management and module development\n\n- **/nixos slash command**: Use this command for Nix-specific queries and tasks, such as:\n  - Searching for packages: `/nixos search <package-name>`\n  - Finding configuration options: `/nixos search <option-name>`\n  - Getting package version information\n  - Researching Home Manager options\n  - Looking up nix-darwin settings\n\nThese specialized tools have access to comprehensive Nix documentation and can provide more accurate, idiomatic solutions for Nix-related work.\n\n## Commands\n\n### Building and Switching Configurations\n```bash\n# Build and switch Darwin configuration (main command)\nu switch\n\n# Just build without switching (ALWAYS TEST THIS FIRST)\n./build system\n\n# Update flake inputs and brew packages\nmake update\n\n# Full upgrade: update, switch, and check\nupgrade hera\n```\n\n### Maintenance Commands\n```bash\n# Verify Nix store integrity\nu check\n\n# Clean old generations (default: 14 days)\nu clean\n\n# Remove all but current generation\nu purge\n\n# Sign store paths with local key\nu sign\n\n# Copy store paths to remote hosts\n copy\n\n# Prepare all projects for travel (rebuild direnv caches)\nu travel-ready\n```\n\n### Development\n```bash\n# Open Nix REPL with current system packages\nu repl\n\n# Rebuild direnv cache for current project\n./bin/de [--no-cache]\n```\n\n## Architecture\n\n### Core Structure\n- **flake.nix**: Main Darwin flake defining system configurations for macOS hosts\n  - Defines darwinConfigurations for hera, clio, and athena\n  - Imports home-manager as a Darwin module\n  - Specifies flake inputs (nixpkgs, nix-darwin, home-manager, emacs-overlay, etc.)\n  - Loads all overlays from the `overlays/` directory\n\n- **nixos/flake.nix**: Separate flake for NixOS configuration (vulcan host)\n  - Independent flake with its own inputs and lock file\n  - Uses nixosSystem instead of darwinSystem\n  - Shares some overlays but has NixOS-specific modules\n\n- **config/**: Host-specific and shared configuration files\n  - `darwin.nix`: System-level Darwin configuration (users, fonts, services, system preferences)\n  - `home.nix`: User-level home-manager configuration (shell, git, development tools)\n  - `packages.nix`: User package declarations (imported by home.nix)\n  - `{hostname}.nix`: Host-specific overrides (e.g., hera.nix, clio.nix)\n    - Merged with shared config using `lib.mkMerge` and host detection\n    - Can override packages, services, or add host-specific settings\n\n- **overlays/**: Custom package overlays organized by category\n  - **Numbered prefixes indicate loading order**: `00-` loads first, then `10-`, then `20-`, etc.\n  - **Loading mechanism**: All `.nix` files in overlays/ are automatically imported by flake.nix\n  - **Categories**:\n    - `00-lib.nix`: Utility functions available to other overlays\n    - `10-emacs.nix`, `10-emacs-packages.nix`: Emacs with MacPort patches and custom packages\n    - `10-haskell.nix`: Haskell package overrides and GHC versions\n    - `10-coq.nix`: Coq theorem prover and related tools\n    - `20-*`: Custom scripts and utilities that depend on earlier overlays\n  - **Overlay pattern**: Each file exports `final: prev: { ... }` where:\n    - `final`: The final package set after all overlays\n    - `prev`: The package set before this overlay\n    - Always use `prev` to reference the previous package version\n    - Use `final` when you need packages from later overlays (careful: can cause infinite recursion)\n\n### Configuration Merging and Precedence\n\n1. **System Configuration Flow** (Darwin):\n   ```\n   flake.nix \\342\\206\\222 darwinConfigurations.${hostname}\n     \\342\\224\\234\\342\\224\\200 imports config/darwin.nix (system-level settings)\n     \\342\\224\\234\\342\\224\\200 applies all overlays/ (in numeric order)\n     \\342\\224\\224\\342\\224\\200 imports home-manager module\n          \\342\\224\\224\\342\\224\\200 imports config/home.nix (user-level settings)\n               \\342\\224\\224\\342\\224\\200 imports config/packages.nix\n   ```\n\n2. **Host-Specific Overrides**:\n   - Host detection: `if pkgs.stdenv.hostPlatform.system == \"...\" then ...`\n   - Conditional imports: `imports = [ ] ++ lib.optional (hostname == \"hera\") ./hera.nix;`\n   - Host-specific packages: Use `lib.mkIf (config.networking.hostName == \"hera\")`\n\n3. **Home-Manager Integration**:\n   - Runs as a Darwin module (not standalone)\n   - User packages installed to `~/.nix-profile`\n   - System packages installed to `/run/current-system`\n   - Home-manager settings take precedence for user environment\n\n### Key Design Patterns\n1. **Flake-based Configuration**: Uses Nix flakes for reproducible system configuration with locked dependencies\n   - All inputs pinned in `flake.lock`\n   - `nix flake update` refreshes all inputs\n   - `nix flake lock --update-input <input>` updates specific input\n\n2. **Overlay System**: Extensive use of overlays to customize packages\n   - Particularly for Emacs (MacPort version) and development tools\n   - Overlays are composable and can reference each other\n   - Use overlays for package modifications, not for creating entirely new packages (use packages/ dir instead)\n\n3. **Host Differentiation**: Configuration varies by hostname with conditional attributes\n   - PostgreSQL only on certain hosts\n   - Different Emacs configurations per host\n   - Host-specific services and packages\n\n4. **Direnv Integration**: Custom `de` script manages per-project Nix shells\n   - Caches built environments in `.envrc.cache`\n   - Supports flakes (`flake.nix`), legacy (`shell.nix`), and Kadena projects\n   - Preserves variables: `BUILDER`, `NIX_CONF`, SSH agent, etc.\n\n5. **Remote Builder Support**: Optional use of remote builders\n   - Set via `BUILDER` environment variable\n   - Used by `de` script and Nix builds\n   - Configured in `darwin.nix` under `nix.buildMachines`\n\n### Important Variables\n- `HOSTNAME`: Current host (hera, clio, athena, or vulcan)\n- `NIX_CONF`: Points to this repository (`~/src/nix`)\n- `BUILDER`: Optional remote builder hostname for Nix builds\n- `MAX_AGE`: Days to keep old generations (default: 14)\n\n### Custom Scripts\n- **bin/de**: Direnv cache builder supporting flakes, shell.nix, and remote builders\n  - Creates `.envrc` and `.envrc.cache` for faster shell activation\n  - Preserves essential environment variables across direnv reloads\n  - Supports Kadena-specific and flake-based projects\n  - Usage: Run in project directory, optionally with `--no-cache` to force rebuild\n\n## Best Practices\n\n### Testing Configuration Changes\n1. **Always build before switching**: `make build` catches errors without affecting the running system\n2. **Review the diff**: Check what packages will change before switching\n3. **Use git**: Commit working configurations before major changes\n4. **Test in stages**: Make small, incremental changes rather than large rewrites\n5. **Keep rollback ready**: Old generations remain available via `darwin-rebuild --list-generations`\n\n### Managing Packages\n- **System vs User packages**:\n  - System packages (`environment.systemPackages`): Daemons, system-wide tools, things that need root\n  - User packages (`home.packages`): Personal tools, development utilities, CLI apps\n  - When in doubt, prefer user packages (easier to manage, faster rebuilds)\n\n- **Adding packages**:\n  1. Search first: Use `/nixos search <package>` or check nixpkgs\n  2. Add to `config/packages.nix` for user packages\n  3. Add to `config/darwin.nix` for system packages\n  4. Build and test: `make build` before `make switch`\n\n- **Custom package versions**:\n  - Use overlays for modifications or version pinning\n  - Place in appropriately numbered overlay file (e.g., `10-custom.nix`)\n  - Reference existing patterns in `overlays/10-*.nix`\n\n### Flake Management\n- **Updating inputs**:\n  - `make update`: Updates all inputs and Homebrew\n  - `nix flake lock --update-input nixpkgs`: Update only nixpkgs\n  - Review `flake.lock` changes before committing\n  - Test after updates: `make build && make switch`\n\n- **Adding new inputs**:\n  1. Add to `inputs` section in `flake.nix`\n  2. Pass to darwinConfigurations via `specialArgs` or module arguments\n  3. Update lock: `nix flake lock`\n  4. Use in config: Access via module arguments\n\n- **Flake update strategy**:\n  - Update regularly (weekly/monthly) to get security fixes\n  - Test updates on non-critical host first\n  - Keep old generations until new config is proven stable\n  - Pin critical package versions in overlays if needed\n\n### Overlay Development\n- **Organization**:\n  - Use numbered prefixes to control load order\n  - Keep related modifications together (e.g., all Emacs changes in one file)\n  - Document non-obvious changes with comments\n  - Test overlays independently when possible\n\n- **Common patterns**:\n  ```nix\n  # Simple package override\n  final: prev: {\n    package-name = prev.package-name.overrideAttrs (old: {\n      version = \"1.2.3\";\n      src = prev.fetchurl { ... };\n    });\n  }\n\n  # Add to package\n  final: prev: {\n    package-name = prev.package-name.overrideAttrs (old: {\n      buildInputs = old.buildInputs ++ [ prev.somelib ];\n    });\n  }\n\n  # Conditional override\n  final: prev: {\n    package-name =\n      if prev.stdenv.isDarwin\n      then prev.package-name.override { enableFeature = true; }\n      else prev.package-name;\n  }\n  ```\n\n- **Debugging overlays**:\n  - Use `nix repl` to test expressions: `make repl`\n  - Check overlay order if changes aren't applying\n  - Look for infinite recursion (using `final` to reference the same package you're defining)\n  - Use `builtins.trace` for debugging: `builtins.trace \"value: ${value}\" expression`\n\n### Secrets and Sensitive Data\n- **Never commit secrets to the repository**\n- **Key management**:\n  - SSH keys referenced in `key-files.nix` but stored outside repo\n  - Private keys in `~/.ssh/`, public keys in config\n- **Passwords and tokens**:\n  - Use environment variables for builds\n  - Consider agenix or sops-nix for encrypted secrets (not currently used in this config)\n- **Git hygiene**:\n  - Review diffs before committing\n  - Use `.gitignore` for local overrides or sensitive files\n\n### Module Organization\n- **Separation of concerns**:\n  - `darwin.nix`: System settings, services, fonts, Nix daemon config\n  - `home.nix`: User environment, shell config, dotfiles\n  - `packages.nix`: Just the package list\n  - Host-specific files: Only settings unique to that machine\n\n- **When to create new modules**:\n  - Feature has >50 lines of configuration\n  - Configuration is reusable across hosts\n  - Logical separation improves maintainability\n  - Use `imports = [ ./modules/feature.nix ];`\n\n## Troubleshooting\n\n### Common Issues\n\n#### Build Failures\n```\nerror: attribute 'packageName' missing\n```\n**Solution**: Package was removed from nixpkgs or renamed. Search for replacement: `/nixos search <package>`\n\n```\nerror: infinite recursion encountered\n```\n**Solution**: Overlay is referencing `final` when it should use `prev`, or circular dependency in config.\n- Check overlay files for `final.packageName` references\n- Use `prev.packageName` to get the previous version\n\n```\nerror: hash mismatch in fixed-output derivation\n```\n**Solution**: Source hash changed (package updated). Update the hash in the overlay or fetch expression.\n\n#### Darwin-Rebuild Errors\n```\nerror: could not set permissions on '/nix/var/nix/profiles/per-user/...'\n```\n**Solution**: Permissions issue. Fix with: `sudo chown -R $(whoami) /nix/var/nix/profiles/per-user/$(whoami)`\n\n```\nerror: profile '/nix/var/nix/profiles/system' does not exist\n```\n**Solution**: Fresh install or profile corruption. Run: `sudo nix-env -p /nix/var/nix/profiles/system --set /run/current-system`\n\n#### Flake Lock Issues\n```\nerror: flake 'git+file://...' does not provide attribute ...\n```\n**Solution**: Flake schema mismatch. Check that outputs match what's being accessed:\n- `nix flake show` to see available outputs\n- Verify `darwinConfigurations.${hostname}` exists in flake.nix\n\n```\nerror: cannot update flake input 'foo' because it is locked\n```\n**Solution**: Remove `flake.lock` entry or use `--update-input foo` flag\n\n#### Home-Manager Issues\n```\nerror: collision between ... and ...\n```\n**Solution**: Same package in both system and user packages, or duplicate in packages list.\n- Remove from one location (prefer user packages)\n- Check for duplicates in `packages.nix`\n\n#### Nix Store Issues\n```\nerror: cannot open connection to remote store 'ssh://...'\n```\n**Solution**: Remote builder unreachable. Check `BUILDER` variable, SSH config, and network.\n\n```\nerror: store path '...' is not valid\n```\n**Solution**: Store corruption. Run `make check` or `nix-store --verify --check-contents --repair`\n\n### Debugging Techniques\n\n1. **Verbose builds**: Add `-v` or `-vv` or `-vvv` for increasing verbosity\n   ```bash\n   darwin-rebuild build --flake .#hera -vv\n   ```\n\n2. **Show trace**: Add `--show-trace` to see full error context\n   ```bash\n   nix build --show-trace\n   ```\n\n3. **Test specific attributes**:\n   ```bash\n   nix eval .#darwinConfigurations.hera.config.environment.systemPackages\n   ```\n\n4. **REPL exploration**:\n   ```bash\n   make repl\n   # Then explore: :lf . to load flake, tab completion works\n   ```\n\n5. **Build logs**: Check detailed logs\n   ```bash\n   nix log /nix/store/...-package-name\n   ```\n\n6. **Diff generations**: Compare what changed\n   ```bash\n   darwin-rebuild --list-generations\n   nix store diff-closures /nix/var/nix/profiles/system-{42,43}-link\n   ```\n\n### Getting Help\n- Check Nix manual: https://nixos.org/manual/nix/stable/\n- nix-darwin options: https://daiderd.com/nix-darwin/manual/\n- Home-manager options: https://nix-community.github.io/home-manager/options.html\n- Search packages/options: Use `/nixos search <query>`\n- NixOS Discourse: https://discourse.nixos.org/\n- Use the nix-pro subagent for Nix-specific questions\n\n## Development Notes\n\n- The configuration uses macOS-specific packages via nix-darwin and Homebrew integration\n- Emacs configuration is heavily customized with MacPort patches and extensive overlays\n- SSH keys are managed via `key-files.nix` for cross-host authentication\n- Projects listed in `~/.config/projects` are automatically managed by update/travel-ready commands\n- Direnv caching significantly speeds up project shell activation\n- Remote builders can be used by setting `BUILDER` environment variable before builds\n\n\n      IMPORTANT: this context may or may not be relevant to your tasks. You should not respond to this context unless it is highly relevant to your task.\n</system-reminder>\n"
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          "text": "Warmup",
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      "text": "You are Claude Code, Anthropic's official CLI for Claude.",
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      "text": "You are a file search specialist for Claude Code, Anthropic's official CLI for Claude. You excel at thoroughly navigating and exploring codebases.\n\nYour strengths:\n- Rapidly finding files using glob patterns\n- Searching code and text with powerful regex patterns\n- Reading and analyzing file contents\n\nGuidelines:\n- Use Glob for broad file pattern matching\n- Use Grep for searching file contents with regex\n- Use Read when you know the specific file path you need to read\n- Use Bash for file operations like copying, moving, or listing directory contents\n- Adapt your search approach based on the thoroughness level specified by the caller\n- Return file paths as absolute paths in your final response\n- For clear communication, avoid using emojis\n- Do not create any files, or run bash commands that modify the user's system state in any way\n\nComplete the user's search request efficiently and report your findings clearly.\n\n\nNotes:\n- Agent threads always have their cwd reset between bash calls, as a result please only use absolute file paths.\n- In your final response always share relevant file names and code snippets. Any file paths you return in your response MUST be absolute. Do NOT use relative paths.\n- For clear communication with the user the assistant MUST avoid using emojis.\n\nHere is useful information about the environment you are running in:\n<env>\nWorking directory: /Users/johnw/src/nix\nIs directory a git repo: Yes\nPlatform: darwin\nOS Version: Darwin 25.0.0\nToday's date: 2025-11-03\n</env>\nYou are powered by the model named Haiku 4.5. The exact model ID is claude-haiku-4-5-20251001.\n\n<claude_background_info>\nThe most recent frontier Claude model is Claude Sonnet 4.5 (model ID: 'claude-sonnet-4-5-20250929').\n</claude_background_info>\n\ngitStatus: This is the git status at the start of the conversation. Note that this status is a snapshot in time, and will not update during the conversation.\nCurrent branch: master\n\nMain branch (you will usually use this for PRs): master\n\nStatus:\n?? imap_reset_dates.py\n\nRecent commits:\naa9fffa Add launchd daemons for cleanup and mssql-server, refactor daemon config\n01020b1 config/packages.nix: Enable github-mcp-server\n08e9e85 darwin, home: Pin Node.js to version 22\n319f8ea config/packages.nix: Add dirscan package\n7b09956 overlays/20-ai: Update llama-cpp to version 6932",
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