I supported hiccup (the syntax) without using hiccup (the library)

I use a combination of my own code along with the hickory library.

Excellent article on GraalVM substitutions: https://blog.frankel.ch/coping-incompatible-code-graalvm-compilation/ This is also the approach taken to fix an issue with GraalVM and Clojure on JDK11 https://github.com/borkdude/clj-reflector-graal-java11-fix