---
name: "inc::latest"
section: "3perl"
platform: "linux"
package: "perl-doc"
version: "5.20.2-3+deb8u11"
release: "Debian 8 (Jessie)"
platforms: ["linux"]
url: "https://new.carta.tech/inc::latest"
---

# inc::latest(3perl)

use modules bundled in inc/ if they are newer than installed ones

## NAME

inc::latest - use modules bundled in inc/ if they are newer than installed ones

## SYNOPSIS

```
  # in Build.PL
  use inc::latest 'Module::Build';
```

## DESCRIPTION

The `"inc::latest"` module helps bootstrap configure-time dependencies for CPAN distributions.  These dependencies get bundled into the `"inc"` directory within a distribution and are used by Build.PL (or Makefile.PL).

Arguments to `"inc::latest"` are module names that are checked against both the current `@INC` array and against specially-named directories in `"inc"`.  If the bundled version is newer than the installed one (or the module isn't installed, then, the bundled directory is added to the start of \<@INC\> and the module is loaded from there.

There are actually two variations of `"inc::latest"` -- one for authors and one for the `"inc"` directory.  For distribution authors, the `"inc::latest"` installed in the system will record modules loaded via `"inc::latest"` and can be used to create the bundled files in `"inc"`, including writing the second variation as `"inc/latest.pm"`.

This second `"inc::latest"` is the one that is loaded in a distribution being installed (e.g. from Build.PL).  This bundled `"inc::latest"` is the one that determines which module to load.

### Special notes on bundling

The `"inc::latest"` module creates bundled directories based on the packlist file of an installed distribution.  Even though `"inc::latest"` takes module name arguments, it is better to think of it as bundling and making available entire *distributions*.  When a module is loaded through `"inc::latest"`, it looks in all bundled distributions in `"inc/"` for a newer module than can be found in the existing `@INC` array.

Thus, the module-name provided should usually be the "top-level" module name of a distribution, though this is not strictly required.  For example, Module::Build has a number of heuristics to map module names to packlists, allowing users to do things like this:

```
  use inc::latest 'Devel::AssertOS::Unix';
```

even though Devel::AssertOS::Unix is contained within the Devel-CheckOS distribution.

At the current time, packlists are required.  Thus, bundling dual-core modules may require a 'forced install' over versions in the latest version of perl in order to create the necessary packlist for bundling.

## USAGE

When calling `"use"`, the bundled `"inc::latest"` takes a single module name and optional arguments to pass to that module's own import method.

```
  use 'inc::latest' 'Foo::Bar' qw/foo bar baz/;
```

### Author-mode

You are in author-mode inc::latest if any of the Author-mode methods are available.  For example:

```
  if ( inc::latest->can('write') ) {
    inc::latest->write('inc');
  }
```

- *loaded\_modules()*

  ```
    my @list = inc::latest->loaded_modules;
  ```

  This takes no arguments and always returns a list of module names requested for loading via "use inc::latest 'MODULE'", regardless of whether the load was successful or not.

- *write()*

  ```
    inc::latest->write( 'inc' );
  ```

  This writes the bundled version of inc::latest to the directory name given as an argument.  It almost all cases, it should be '`"inc"`'.

- *bundle\_module()*

  ```
    for my $mod ( inc::latest->loaded_modules ) {
      inc::latest->bundle_module($mod, $dir);
    }
  ```

  If `$mod` corresponds to a packlist, then this function creates a specially-named directory in `$dir` and copies all .pm files from the modlist to the new directory (which almost always should just be 'inc').  For example, if Foo::Bar is the name of the module, and `$dir` is 'inc', then the directory would be 'inc/inc\_Foo-Bar' and contain files like this:

  ```
    inc/inc_Foo-Bar/Foo/Bar.pm
  ```

  Currently, `$mod` **must** have a packlist.  If this is not the case (e.g. for a dual-core module), then the bundling will fail.  You may be able to create a packlist by forced installing the module on top of the version that came with core Perl.

### As bundled in inc/

All methods are private.  Only the `"import"` method is public.

## AUTHOR

Eric Wilhelm \<ewilhelm@cpan.org\>, David Golden \<dagolden@cpan.org\>

## COPYRIGHT

Copyright (c) 2009 by Eric Wilhelm and David Golden

This library is free software; you can redistribute it and/or modify it under the same terms as Perl itself.

## SEE ALSO

Module::Build