If you run into the error “error invoking target irman ioracle of makefile” while trying to install Oracle Database, and the log shows a missing ljavavm12 library, you may need to copy the java library like so:

cp ./u01/app/oracle/product/12.1.0/db_1/javavm/jdk/jdk6/lib/libjavavm12.a ./u01/app/oracle/product/12.1.0/db_1/lib/