Cann't compile with YAML_DIR=

I cann’t install kong wth YML_DIR option.
It always get a
required symbol ‘yaml_document_initialize’ not found in any of libc, libyaml
However, using the system’s libyaml is ok.

The variable to luarocks install is YAML_DIR. Here is an example of it being used in kong-env.

Why are you installing a local libyaml?