Fix compilation on Windows.

Q_NORETURN belongs *before* the rest of the function declaration...

Change-Id: Ib91cc7902f35acdb42d0039998b02b8f26f96eea
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Throw a proper error when encountering invalid outputArtifact values.

A user can easily trigger this condition, so we can't assert on it.

Change-Id: Id26ee13dbcea6207da316f454ecf357a284be2da
Reviewed-by: Oswald Buddenhagen <oswald.buddenhagen@theqtcompany.com>
Reviewed-by: Christian Kandeler <christian.kandeler@theqtcompany.com>