Why can’t I use @ignore directives in @thin and @file trees?
@ignore can only be used in the root node of @file trees. It tells Leo to ignore the tree. The @ignore directive can not be used elsewhere in @thin trees and @file trees because of the way Leo recreates outlines from derived files. This is an absolutely crucial restriction and will never go away. For a few more details, see Leo 4.0: Eliminating error ‘recovery’ in Chapter 9: History of Leo. There are several workaround, as shown in LeoPy.