are you sure it works with WildFly 10? As far I can say JBOSS_MODULEPATH behaves the same with WildFly 10 and WildFly 14. It's "module add" command that doesn't take JBOSS_MODULEPATH variable into account. Since WildFly 11 you can use additional parameter "--module-root-dir=<path>" to specify where the module will be created.
module add --name=com.oracle.ojdbc8 --resources=/tmp/ojdbc8.jar --dependencies=javax.api,javax.transaction.api,javax.resource.api --module-root-dir=<path>
Thanks! Using "module add" with the parameter "--module-root--dir=<path> solves the problem.
Yes you are also right about JBOSS_MODULEPATH. It works the same in Wildfly-10 and Wildfly-14 when it comes to how Wildfly locates the modules that are installed. The problem I had was that the jboss-cli script "module add" no longer takes the JBOSS_MODULEPATH.