On 15 July 2018 at 20:07, Ben Gamari
The GHC development team is pleased to announce the second alpha release leading up to GHC 8.6.1.
The following MVE uses the gitrev library ( http://hackage.haskell.org/package/gitrev ): $ cat Test.hs {-# LANGUAGE TemplateHaskell #-} module Main where import Development.GitRev commitInfo :: Maybe String commitInfo = case $(gitHash) of "UNKNOWN" -> Nothing hash -> Just hash main :: IO () main = print commitInfo The MVE compiles *without* warnings with different versions of GHC (e.g. 8.4.3) but with GHC 8.6.1-alpha2 I get the following warning: $ ghc Test.hs Test.hs:10:3: warning: [-Woverlapping-patterns] Pattern match is redundant In a case alternative: hash -> ... | 10 | hash -> Just hash | ^^^^^^^^^^^^^^^^^^^^^^ Linking Test ... Is it a bug or is it the expected behaviour? Best, -- Andrés