# Diff Nix
A blazingly fast tool to diff Nix related things.
Currently only supports closures (a derivation graph, such as a system build or
package).

## Usage
```bash
$ dix --help
Diff Nix
Usage: dix [OPTIONS] <OLD_PATH> <NEW_PATH>
Arguments:
<OLD_PATH>
<NEW_PATH>
Options:
-v, --verbose...
Increase logging verbosity
-q, --quiet...
Decrease logging verbosity
--color <WHEN>
Controls when to use color
[default: auto]
[possible values: auto, always, never]
--force-correctness
Fall back to a backend chain that skips SQLite immutable mode.
This is relevant if the output of dix is to be used for more critical applications and not just as human-readable overview.
The default backend falls back to opening Nix's SQLite database with `?immutable=1` if the normal connection fails. That is faster than Nix commands, but can be inaccurate if the database is being written to at the same time.
--output <OUTPUT>
Select the output format to use
Possible values:
- human: Output in the default dix format highlighting version changes
- json: Display the output as JSON for machine parsing (requires `json` feature)
[default: human]
-h, --help
Print help (see a summary with '-h')
-V, --version
Print version
$ dix /nix/var/profiles/system-69-link /run/current-system
```
# Usage in CI
If you're planning on using dix in CI, you might want to set the
`--force-correctness` flag to ensure that the results are definitely accurate.\
Dix will fall back to a connection using `?immutable=1` to Nix's SQLite database
if it fails connecting normally; This can however result in inaccurate output if
the database is being written to at the same time.\
Passing `--force-correctness` will make dix fall back to Nix commands if
connection to the database fails, which ensures correct output, potentially at
the cost of speed.
## Releasing
`dix-diff` is a separate crate because it owns the pure package/version diff
engine. Publish it before publishing `dix`; the `dix` package depends on the
same exact `dix-diff` version.
```sh
cargo publish -p dix-diff
cargo publish -p dix
```
## Contributing
If you have any problems, feature requests or want to contribute code or want to
provide input in some other way, feel free to create an issue or a pull request!
## Thanks
Huge thanks to [nvd](https://git.sr.ht/~khumba/nvd) for the original idea! Dix
is heavily inspired by this and basically just a "Rewrite it in Rust" version of
nvd, with a few things like version diffing done better.
Furthermore, many thanks to the amazing people who made this projects possible
by contributing code and offering advice:
- [@Dragyx](https://github.com/Dragyx) - Cool SQL queries. Much of dix's speed
is thanks to him.
- [@NotAShelf](https://github.com/NotAShelf) - Implementing proper error
handling.
- [@RGBCube](https://github.com/RGBCube) - Giving the codebase a deep scrub.
## License
Dix is licensed under [GPLv3](LICENSE.md). See the license file for more
details.