Liquibase drop constraint

I am truing to drop unique constraint using Liquibase 





and i am using maven. So when i first run mvn liquibase:update, Liquibase drops appropriate constraints, but when after that i run mvn clean package it obviously fails because there is no constraints in db. So i couldn’t find appropriate maven scope or property to disable Liquibase when running mvn clean package or install.  Maybe there are some preconditions which can help me?

There isn’t an existing uniqueConstraintExists precondition, unfortuantely, but you could use an that queries the info_schema.

I’m not a big maven user, is the root problem that udpates shouldn’t happen with clean package or install, but only on update? I’m not sure how to modify that.