Middleman not copying images to build from source

I’m using Middleman 4.2 and having trouble with image assets.

In my config I have:

set :images_dir, 'assets/images'
set :css_dir, 'assets/stylesheets'
set :js_dir, 'assets/javascripts'

But when MM builds, images in source/assets/images are not copied to anywhere in build. Other assets are just fine. I’ve checked the permissions on images, added more images, added directory structure to the source images directory, but nothing. Not too sure what to try next.

What might I be missing? Thanks for your time!

Additional details:

My config also contains

configure :build do
  activate :asset_hash

and I use webpack for a pipeline, but as far as I understand, webpack doesn’t handle images and it seems middleman is still supposed to.

Okay so, the issue seems to have been that images need to be within source/. I’m assuming because I’m using webpack, the other assets were okay outside of source, but since webpack doesn’t handle images, they needed to remain there. A relative path with ../ didn’t resolve this, so it seems to be a strict requirement.