# nvft (nvfetcher + tools)

A Nix package that combines nvfetcher source updates with automatic Go vendor hash calculation.

## Usage

```bash
# Enter the nix-shell (makes nvft available)
nix-shell

# Run the updater
nvft
```

This will:
1. Save existing vendorHash and source hashes
2. Run `nvfetcher` to update all source versions and hashes in `_sources/generated.nix`
3. Restore saved vendorHash values
4. Check if source hash changed - if yes, recalculate vendorHash; if no, skip (fast!)
5. Update `vendorHash` in `_sources/generated.nix` only if needed

## Configuration

Go packages that need vendor hash updates are configured in the `GO_PACKAGES` array within the script.

Currently configured packages:
- `mender-cli` -> `modules/home/terminal/hr/mender-cli.nix`

To add more Go packages, edit `pkgs/nvft/default.nix` and add entries to the `GO_PACKAGES` array.

## How it Works

For each Go package:
1. Compares old vs new source hash to detect updates
2. If source unchanged, keeps existing vendorHash (fast)
3. If source changed, creates a temporary build with `lib.fakeHash`
4. Attempts to build, which fails with the correct hash
5. Extracts the correct hash from the error message
6. Updates `vendorHash` directly in `_sources/generated.nix` alongside the source information

## Package Usage

Go packages read vendorHash from the sources:

```nix
let
  src = sources.mender-cli;
in
buildGoModule {
  inherit (src) pname version src vendorHash;
  # ... rest of package
}
```

The vendorHash is stored in `_sources/generated.nix` alongside the version and source hash, keeping all auto-generated values in one place.