This is also valid for interfaces. If an error occurs, the part of the interface preceding the error is computed. After typechecking, pressing the right button pops up a menu giving the type of the pointed expression, and eventually allowing to follow some links. Clear errors dismisses type-checker error messages and warnings. The executed subshell is given the current load path.
File use a source file or load a bytecode file.
You may also import the browser's path into the subprocess. Signal C-c interrupts, and you can also kill the subprocess.