#11558: Using Cabal 1.22 against GHC 8.0 results in terrible errors -------------------------------------+------------------------------------- Reporter: bgamari | Owner: Type: bug | Status: new Priority: highest | Milestone: 8.0.1 Component: Package | Version: 8.0.1-rc1 system | Keywords: | Operating System: Unknown/Multiple Architecture: | Type of failure: Incorrect Unknown/Multiple | warning at compile-time Test Case: | Blocked By: Blocking: | Related Tickets: Differential Rev(s): | Wiki Page: -------------------------------------+------------------------------------- GHC 8.0 will require Cabal >1.22 due to a variety of interface changes (see #10714, Phab:D1780, https://mail.haskell.org/pipermail/ghc- devs/2016-January/010978.html). Unfortunately things currently blow up late in compilation with a seemingly unrelated error when this requirement isn't met. Namely, we complain about missing interface files for dependencies. For instance, {{{ Text/Parsec/Prim.hs:85:1: error: Bad interface file: /root/.cabal/lib/x86_64-linux- ghc-8.0.0.20160204/mtl-2.2.1-9wMhzcfsAXi7cNtl9n7svO/Control/Monad/Cont/Class.hi Something is amiss; requested module mtl-2.2.1@mtl-2.2.1-1af5dabd2d7abb688f2145aec87badc4:Control.Monad.Cont.Class differs from name found in the interface file mtl_9wMhzcfsAXi7cNtl9n7svO:Control.Monad.Cont.Class }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11558 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler