message: Change default ocaml build chain to 'docker'
diff: @@ -4,7 +4,7 @@ use std::path::{Path, PathBuf};
  use std::process::Command;
  fn run_builder(lib_dir: &PathBuf) {
  - let build_chain = env::var("OCAML_BUILD_CHAIN").unwrap_or("local".to_string());
  + let build_chain = env::var("OCAML_BUILD_CHAIN").unwrap_or("docker".to_string());
  match build_chain.as_ref() {
  "local" => {
  