> ## Documentation Index
> Fetch the complete documentation index at: https://flox-tanja-docs-description.mintlify.site/llms.txt
> Use this file to discover all available pages before exploring further.

# flox build update catalogs

## NAME

flox-build-update-catalogs - Update the project catalog lockfile

## SYNOPSIS

```text theme={null}
flox [<general-options>] build update-catalogs
     [-d=<path>]
```

## DESCRIPTION

Scan the project’s Nix expression builds (`.nix` files under
`.flox/pkgs/`) for `catalogs.<catalog>.<package>` references and lock
them to `.flox/catalog.lock`.

There is exactly one catalog lock per project. It pins the source of
every catalog reference the project’s expressions make, resolved as a
union in a single request, so that every build of a revision evaluates
against one consistent set of inputs. Commit the file alongside the
manifest.

A committed lock is used exactly as it is found: `flox build` and
`flox publish` never rewrite it. When the project’s expressions gain a
reference the lock does not cover, re-run `flox build update-catalogs`
and commit the result. References the scanner cannot fully resolve are
pinned conservatively; a package newly referenced beneath one of them
cannot be detected as missing from the lock and instead fails during
evaluation. Re-running `flox build update-catalogs` resolves this as
well. Without a committed lock, builds resolve the references of the
packages being built fresh on every invocation.

## OPTIONS

### Environment Options

If no environment is specified for an environment command, the
environment in the current directory or the active environment that was
last activated is used.

`-d`, `--dir`\
Path containing a .flox/ directory.

### General Options

`-h`, `--help`\
Prints help information.

The following options can be passed when running any `flox` subcommand
but must be specified *before* the subcommand.

`-v`, `--verbose`\
Increase logging verbosity. Invoke multiple times for increasing detail.

`-q`, `--quiet`\
Silence logs except for errors.

## SEE ALSO

[`flox-build`](/man/flox-build)
[`flox-publish`](/man/flox-publish)