#16211: Recompiling results in a missing instance -------------------------------------+------------------------------------- Reporter: crockeea | Owner: (none) Type: bug | Status: new Priority: normal | Milestone: Component: Compiler | Version: 8.6.3 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: Type of failure: Incorrect | Unknown/Multiple error/warning at compile-time | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): Wiki Page: | -------------------------------------+------------------------------------- Comment (by crockeea): Simon, it looks like you have a pretty outdated Hackage snapshot. Perhaps try a `cabal update`? The latest version of monad-classes is 0.3.2.2, but your failed installation was trying 0.3.2.0. {{{
ghc --version The Glorious Glasgow Haskell Compilation System, version 8.6.3
cabal --version cabal-install version 2.4.1.0 compiled using version 2.4.1.0 of the Cabal library
cd bug
cabal sandbox init
cabal install --only-dependencies Starting peano-0.1.0.1 Starting base-orphans-0.8 Starting reflection-2.1.4 Starting primitive-0.6.4.0 Building base-orphans-0.8 Building reflection-2.1.4 Building primitive-0.6.4.0 Building peano-0.1.0.1 Completed base-orphans-0.8 Starting transformers-compat-0.6.2 Completed peano-0.1.0.1 Building transformers-compat-0.6.2 Completed reflection-2.1.4 Completed transformers-compat-0.6.2 Starting mmorph-1.1.2 Starting transformers-base-0.4.5.2 Building transformers-base-0.4.5.2 Building mmorph-1.1.2 Completed transformers-base-0.4.5.2 Starting monad-control-1.0.2.3 Completed mmorph-1.1.2 Completed primitive-0.6.4.0 Building monad-control-1.0.2.3 Completed monad-control-1.0.2.3 Starting monad-classes-0.3.2.2 Building monad-classes-0.3.2.2 Completed monad-classes-0.3.2.2
cabal build <success> }}}
-- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/16211#comment:4 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler