Pattern match warnings in Hadrian

When compiling Hadrian we get lots of warnings like

src/Rules/Libffi.hs:199:61: warning: [-Wincomplete-uni-patterns]
    Pattern match(es) are non-exhaustive
    In a lambda abstraction:
        Patterns of type ‘[FilePath]’ not matched:
            []
            [[]]
            [(_:_)]
            ([]:[]:_:_)
            ...
    |
199 |     fmap (libffiPath -/-) ["Makefile.in", "configure" ] &%> \[mkIn, _] -> do
    |                                                             ^^^^^^^^^^^^^^^^...

where "lots" is at least 8.

Can we not fill in the missing patterns, or suppress the warning? It's distracting.