flake-watcher

Build a local flake everytime its files change.

flake-watcher will print every new output path to stdout. Errors will be logged to stderr.

Installation

To run without installing you can use

shell nix run github:zebreus/flake-watcher

You can install the flake with nix profile install github:zebreus/flake-watcher . flake-watcher is also available on crates.io.

Examples

Run on the default installable of the flake in the current directory. This will build the default installable every time a file in the flake changes.

shell $ flake-watcher .#default /nix/store/wgjr46wxma9cl9wa5csxn22p9vk81rw7-flake-watcher-0.1.0 /nix/store/liin7xdrpd6zj246yz2nrzm9qhgr0ycx-flake-watcher-0.1.0 /nix/store/4cixv5qz39v20a4mazzbm2g4bb64y9l8-flake-watcher-0.1.0

See all options:

```shell $ flake-watcher --help Usage: flake-watcher [OPTIONS] [INSTALLABLE] [-- ...]

Arguments: [INSTALLABLE] The flake output that will get watched. Example: .#foo [NIXBUILDOPTIONS]... Additional options passed to nix build

Options: --skip-initial-build Usually the flake is build once after starting flake-watcher even if no changes were made. This option skips that initial build -h, --help Print help -V, --version Print version ```

Motivation

I wanted to build a document with a nix flake and have it update every time I modify the sources. I also wanted to be able to use the same flake to build the document in CI. Originally I planned to integrate a reloading webserver in flake-watcher but I decided to keep it simple and just print the new output path to stdout. This way you can pipe the output to any other program you want. Also I wasted enough time doing this, maybe I'll add a webserver later.

```bash

The flake output contains html files that get hosted with a reloading webserver

export TEMPDIR=$(mktemp -d) nix run nixpkgs#python39Packages.livereload $TEMPDIR & flake-watcher | xargs -I {} cp -Trf {} $TEMP_DIR ```