There is some catch about library thing.
intellij-arend needs to be in the same dir as Arend
arend-lib needs to have Arend with precompiled something as well.
Since I want to have arend libs folder to be clean from plugin my workflow is the following.
1. Clone Arend, intellij-arend and arend-lib in the same dir \ or pull last changes
2. ln -s arend-lib <arend-libs>
3. cd intellij-arend
4. gradle-or-gradlew buildPlugin
5. cd ../Arend
6. gradle-or-gradlew api:assemble
7. cd ../arend-lib/meta
8. gradle-or-gradlew assemble