How to explicitly exclude directories from being indexed in Rider

Background

Solution might contain folders that are for sure shouldn't be indexed, for example, deployment/cicd related files.

Question

How to explicitly exclude these files from being indexed?

Answer

Right-click on a directory in the Solution Explorer and select Tools | Stop Index:

Another option is to write into .idea/.idea.{solution}/.indexlayout.xml. It allows accurate specifying the folders for exclude/include:

    <explicitIncludes>
      <Path>src/Infra/Something</Path>
    </explicitIncludes>
    <explicitExcludes>
      <Path>src/Infra/Something/Env/UAT</Path>
      <Path>src/Infra/Something/Env/Past</Path>
    </explicitExcludes>