Assets are missing from NPM bundle

[Panoplos]

When installing from npm (yarn), all themes/*/assets are missing now.

Installed with

⟩ yarn add semantic-ui-less --dev
yarn add v1.1.0
[1/5] Resolving packages...
[2/5] Fetching packages...
[3/5] Linking dependencies...
[4/5] Building fresh packages...
[5/5] Cleaning modules...
success Saved lockfile.
success Saved 1 new dependency.
└─ semantic-ui-less@2.2.12
Done in 13.40s.

Assets grep:

⟩ find node_modules/semantic-ui-less | grep assets

And of course, my webpack build fails, now.