Re: [GHC] #11661: Missing MonadFail instance for Q monad from TemplateHaskell

#11661: Missing MonadFail instance for Q monad from TemplateHaskell -------------------------------------+------------------------------------- Reporter: PeterTrsko | Owner: Type: bug | Status: patch Priority: normal | Milestone: 8.0.1 Component: Template Haskell | Version: 8.0.1-rc2 Resolution: | Keywords: Operating System: Unknown/Multiple | Architecture: | Unknown/Multiple Type of failure: None/Unknown | Test Case: Blocked By: | Blocking: Related Tickets: | Differential Rev(s): phab:D1982 Wiki Page: | -------------------------------------+------------------------------------- Comment (by Herbert Valerio Riedel ): In [changeset:"1c76e1686bd4291556ae9357151f256c805b4b5d/ghc" 1c76e16/ghc]: {{{ #!CommitTicketReference repository="ghc" revision="1c76e1686bd4291556ae9357151f256c805b4b5d" template-haskell: define `MonadFail Q` instance When `MonadFail`is available, this patch makes `MonadFail` a superclass of `Quasi`, and `Q` an instance of `MonadFail`. NB: Since f16ddcee0c64a92ab911a7841a8cf64e3ac671fd, we need to be able to compile `template-haskell` with stage0 compilers that don't provide a `MonadFail` class yet. Once we reach GHC 8.3 development we can drop the CPP conditionals again. Addresses #11661 Reviewed By: bgamari, goldfire Differential Revision: https://phabricator.haskell.org/D1982 }}} -- Ticket URL: http://ghc.haskell.org/trac/ghc/ticket/11661#comment:10 GHC http://www.haskell.org/ghc/ The Glasgow Haskell Compiler