-- dependencies:
--
-- test
-- |_______
-- |       |
-- foo     bar
-- |       |_____
-- |       |     |
-- baz     baz   (quux for bar >= 0.3)
--
-- We can't use the latest foo, because we have a <= 0.2.0 restriction.
-- We also can't use foo-0.1.0, because it transitively depends on baz < 0.1.0,
-- which is not installed. So foo-0.2.0 it is.
--
-- foo-0.2.0 requires baz >= 0.2.0, but baz-0.3.0 requires quux, which is
-- not installed. So baz-0.2.0 it is. So, we can't use bar-0.1.1,
-- which requires baz < 0.2.0. Hence, bar-0.1.0 it is, but this
-- requires prz, which is not installed. And so this fails.
package test
depends = foo <= 0.2.0
        , bar >= 0.1.0