cabal-install-1.18 on GHC-6.12

I am trying to compile cabal-install-1.18.0.2 on GHC-6.12.1. It aborts with: ... [12 of 73] Compiling Distribution.Client.Compat.Semaphore ( Distribution/Client/Compat/Semaphore.hs, dist/build/cabal/cabal-tmp/Distribution/Client/Compat/Semaphore.o ) Distribution/Client/Compat/Semaphore.hs:12:26: Module `Control.Exception' does not export `mask_' That is, you must either narrow the dependency on 'base' or avoid 'mask_'.