Your requirements could not be resolved to an installable set of packages.

[mantismamita]

After composer install I'm getting
Warning: The lock file is not up to date with the latest changes in composer.json. You may be getting outdated dependencies. Run update to update them.

followed by Your requirements could not be resolved to an installable set of packages.

So no vendor folder is installed.

[mantismamita]

Not using VVV by the way but I do have npm installed

Problem 1
- Installation request for composer/installers v1.0.22 -> satisfiable by composer/installers[v1.0.22].
- composer/installers v1.0.22 requires composer-plugin-api 1.0.0 -> no matching package found.

Potential causes:

• A typo in the package name
• The package is not available in a stable-enough version according to your minimum-stability setting
  see https://getcomposer.org/doc/04-schema.md#minimum-stability for more details.

[mantismamita]

composer update solves that :)