A test using javax.smartcardio API fails compilation even if @modules java.smartcardio is specified because java.smartcardio module is shown up in the default root set in the runtime.

java.smartcardio is not required by java.se and so it will be excluded in the root set, in the same category as the EE modules (as it's java.* namespace).

java.smartcardio is resolved in the boot layer during service binding.

compiler does not do service binding and so java.smartcardio is not in the default root set during compile time.