The option is documented as required, but it's currently not being validated. This leads to strange side effects such as ones describe in #1628.
I also took the liberty of adding modifiers to the base columpcompiler as it currently does not have this property, but it should.
Ensure that 'client' is provided in knex config object
sqlite3 columncompiler: Assign 'modifiers' --after-- super() call.
oracle columncompiler: Assign 'modifiers' --after-- super() call.