From 94662bffc6385c43da8941e09542a6b3d443ed70 Mon Sep 17 00:00:00 2001
From: Peter Simons <simons@cryp.to>
Date: Sat, 21 Sep 2019 20:55:17 +0200
Subject: [PATCH] XMonad.Util.Invisible: fix build with GHC 8.8.1

This change needs base-4.9.0.0 or later so that we can
include Control.Monad.Fail. We could jump through hoops to
support older compilers still, but it feels like it's not
worthwhile.
---
 XMonad/Util/Invisible.hs | 7 ++++---
 xmonad-contrib.cabal     | 4 ++--
 2 files changed, 6 insertions(+), 5 deletions(-)

diff --git a/XMonad/Util/Invisible.hs b/XMonad/Util/Invisible.hs
index 2fa8b2bd..e1523166 100644
--- a/XMonad/Util/Invisible.hs
+++ b/XMonad/Util/Invisible.hs
@@ -23,6 +23,7 @@ module XMonad.Util.Invisible (
                             ) where
 
 import Control.Applicative
+import Control.Monad.Fail
 
 -- $usage
 -- A wrapper data type to store layout state that shouldn't be persisted across
@@ -30,10 +31,10 @@ import Control.Applicative
 -- Invisible derives trivial definitions for Read and Show, so the wrapped data
 -- type need not do so.
 
-newtype Invisible m a = I (m a) deriving (Monad, Applicative, Functor)
+newtype Invisible m a = I (m a) deriving (Monad, MonadFail, Applicative, Functor)
 
-instance (Functor m, Monad m) => Read (Invisible m a) where
-    readsPrec _ s = [(fail "Read Invisible", s)]
+instance (Functor m, Monad m, MonadFail m) => Read (Invisible m a) where
+    readsPrec _ s = [(Control.Monad.Fail.fail "Read Invisible", s)]
 
 instance Monad m => Show (Invisible m a) where
     show _ = ""
diff --git a/xmonad-contrib.cabal b/xmonad-contrib.cabal
index 5591cdb4..754004f4 100644
--- a/xmonad-contrib.cabal
+++ b/xmonad-contrib.cabal
@@ -36,7 +36,7 @@ cabal-version:      >= 1.6
 build-type:         Simple
 bug-reports:        https://github.com/xmonad/xmonad-contrib/issues
 
-tested-with: GHC==7.8.4, GHC==7.10.3, GHC==8.0.1, GHC==8.2.2, GHC==8.4.3, GHC==8.6.1
+tested-with: GHC==8.0.1, GHC==8.2.2, GHC==8.4.3, GHC==8.6.1
 
 source-repository head
   type:     git
@@ -52,7 +52,7 @@ flag testing
   default: False
 
 library
-    build-depends: base >= 4.5 && < 5,
+    build-depends: base >= 4.9 && < 5,
                    bytestring >= 0.10 && < 0.11,
                    containers >= 0.5 && < 0.7,
                    directory,