I would like to understand how Grunt compiles sources in Magento 2.
I have installed Grunt on my server and set my Magento 2 project (add Gruntfile.js and update dev/tools/grunt/configs/themes.js to add my theme) I have Less in app/design/frontend////web/css/.
I tried to run grunt:exec and Grunt compiles all Less in all Magento Modules (in my app/design/...) to pub/static/frontend///. But Less in my custom modules (in my app/design) is not compiled.
Tests : When I run grunt watch and I modify Less in app/design/frontend////web/css/, it works. When I run grunt watch and I modify Less in app/design/frontend////web/css/, it does not work.