[ackfoobar]

> imperative based build systems (Gradle, Ant, now Mill)

Build code in Mill is pretty declarative. You're using the word to mean "not 'pure, serialized data'".

> IDEs cannot read imperative statemetns

They can, however, run the code to dump the structure.

It's easy for code to embed pure data; on the flip side it's hard to encode behaviour in serialized data. More often than custom Maven plugins I see people just drop down to using shell.