Error on interactions package/import typo

If I type

import mypackage.mysubpackag.*

(having mispelled "mysubpackage") in the interactions pane, there is
no signal that I've made a mistake. I would propose defining any
package or import statement

package <PATH>;

or

import <PATH>.*;

where <PATH> refers to a package that does not exist (according to
the classpath) as an error.