I tried current dev.
and Main.qml in the same directory:
I expected error about not existing property "y" and wrong type of initializer of "x",
but got no output and 0 exit code.
While for example qmlscene report errors:
and if I removed "y" it will report about wrong type of initializer of "x".
I tried "qmllint Main.qml" and also "qmllint Foo.qml Main.qml".
I also I tried to put Foo.qml into module, and import explicitly.
But situation was the same not error about not existing property and "int" vs "string" for "x" init.