Ticket #3172 (closed bug: fixed)
syb-0.1.0.1 doesn't require base >= 4 in its .cabal file
the syb package imports Data.Data, so it needs base-4.*.
syb-0.1.0.0 "correctly" depends on base >= 4 (it's more future proof to use an upper bound too), but syb-0.1.0.1 just uses base with no version range specified. This leads cabal-install to think it's safe to use base-3 making the build fail.