git-annex: apply patch to fix the build with ghc-8.8.x

Unfortunately, we cannot compile git-annex with S3 support in an
LTS-15.x environment, because the 'aws' library hasn't updated to
version 3.x of the 'network' library [1]. I tried whether it's
possible to build git-annex with an older version of network, but
the amount of overrides we'd have to configure to accomplish that
got out of hand quickly. So I disabled aws support [2]. If you
need S3 support in git-annex, please help upstream to update
'aws' so that it builds with recent versions of 'network'.

[1] https://github.com/aristidb/aws/issues/264
[2] https://github.com/NixOS/cabal2nix/commit/1d0459f40e0fa7483fc5c482dcbca1e1db4c40db

2 files changed, 126 insertions, 1 deletions

diff --git a/pkgs/development/haskell-modules/configuration-common.nix b/pkgs/development/haskell-modules/configuration-common.nix
index 67afb5c0bc2d..67bf8684bf72 100644
--- a/pkgs/development/haskell-modules/configuration-common.nix
+++ b/pkgs/development/haskell-modules/configuration-common.nix
@@ -69,7 +69,7 @@ self: super: {
 
   # The Hackage tarball is purposefully broken, because it's not intended to be, like, useful.
   # https://git-annex.branchable.com/bugs/bash_completion_file_is_missing_in_the_6.20160527_tarball_on_hackage/
-  git-annex = (overrideSrc super.git-annex {
+  git-annex = (overrideSrc (appendPatch super.git-annex ./patches/git-annex-fix-build-with-ghc-8.8.x.patch) {
     src = pkgs.fetchgit {
       name = "git-annex-${super.git-annex.version}-src";
       url = "git://git-annex.branchable.com/";
diff --git a/pkgs/development/haskell-modules/patches/git-annex-fix-build-with-ghc-8.8.x.patch b/pkgs/development/haskell-modules/patches/git-annex-fix-build-with-ghc-8.8.x.patch
new file mode 100644
index 000000000000..e28a1f5949ee
--- /dev/null
+++ b/pkgs/development/haskell-modules/patches/git-annex-fix-build-with-ghc-8.8.x.patch
@@ -0,0 +1,125 @@
+From f8d8959e43abd88c5e977079f0948e45cf4c0b0c Mon Sep 17 00:00:00 2001
+From: Peter Simons <simons@cryp.to>
+Date: Fri, 28 Feb 2020 11:56:48 +0100
+Subject: [PATCH] Fix build with ghc-8.8.x.
+
+The 'fail' method has been moved to the 'MonadFail' class. I made the changes
+so that the code still compiles with previous versions of 'base' that don't
+have the new MonadFail class exported by Prelude yet.
+---
+ CmdLine/GitAnnex/Options.hs | 5 +++--
+ Command/Expire.hs           | 5 +++--
+ Command/Init.hs             | 7 ++++---
+ Utility/HumanTime.hs        | 5 +++--
+ 4 files changed, 13 insertions(+), 9 deletions(-)
+
+diff --git a/CmdLine/GitAnnex/Options.hs b/CmdLine/GitAnnex/Options.hs
+index 030c83dd5..a9a36d76f 100644
+--- a/CmdLine/GitAnnex/Options.hs
++++ b/CmdLine/GitAnnex/Options.hs
+@@ -9,6 +9,7 @@
+ 
+ module CmdLine.GitAnnex.Options where
+ 
++import Control.Monad.Fail as Fail ( MonadFail(..) )
+ import Options.Applicative
+ import qualified Data.Map as M
+ 
+@@ -215,8 +216,8 @@ parseAllOption = flag' WantAllKeys
+ 	<> help "operate on all versions of all files"
+ 	)
+ 
+-parseKey :: Monad m => String -> m Key
+-parseKey = maybe (fail "invalid key") return . deserializeKey
++parseKey :: MonadFail m => String -> m Key
++parseKey = maybe (Fail.fail "invalid key") return . deserializeKey
+ 
+ -- Options to match properties of annexed files.
+ annexedMatchingOptions :: [GlobalOption]
+diff --git a/Command/Expire.hs b/Command/Expire.hs
+index 83c38e569..37dc33883 100644
+--- a/Command/Expire.hs
++++ b/Command/Expire.hs
+@@ -17,6 +17,7 @@ import Annex.VectorClock
+ import qualified Remote
+ import Utility.HumanTime
+ 
++import Control.Monad.Fail as Fail ( MonadFail(..) )
+ import Data.Time.Clock.POSIX
+ import qualified Data.Map as M
+ 
+@@ -105,9 +106,9 @@ parseExpire ps = do
+ 		Nothing -> giveup $ "bad expire time: " ++ s
+ 		Just d -> Just (now - durationToPOSIXTime d)
+ 
+-parseActivity :: Monad m => String -> m Activity
++parseActivity :: MonadFail m => String -> m Activity
+ parseActivity s = case readish s of
+-	Nothing -> fail $ "Unknown activity. Choose from: " ++ 
++	Nothing -> Fail.fail $ "Unknown activity. Choose from: " ++ 
+ 		unwords (map show [minBound..maxBound :: Activity])
+ 	Just v -> return v
+ 
+diff --git a/Command/Init.hs b/Command/Init.hs
+index db6cb14fb..879a1110f 100644
+--- a/Command/Init.hs
++++ b/Command/Init.hs
+@@ -13,6 +13,7 @@ import Annex.Version
+ import Types.RepoVersion
+ import qualified Annex.SpecialRemote
+ 
++import Control.Monad.Fail as Fail ( MonadFail(..) )
+ import qualified Data.Map as M
+ 	
+ cmd :: Command
+@@ -33,14 +34,14 @@ optParser desc = InitOptions
+ 		<> help "Override default annex.version"
+ 		))
+ 
+-parseRepoVersion :: Monad m => String -> m RepoVersion
++parseRepoVersion :: MonadFail m => String -> m RepoVersion
+ parseRepoVersion s = case RepoVersion <$> readish s of
+-	Nothing -> fail $ "version parse error"
++	Nothing -> Fail.fail $ "version parse error"
+ 	Just v
+ 		| v `elem` supportedVersions -> return v
+ 		| otherwise -> case M.lookup v autoUpgradeableVersions of
+ 			Just v' -> return v'
+-			Nothing -> fail $ s ++ " is not a currently supported repository version"
++			Nothing -> Fail.fail $ s ++ " is not a currently supported repository version"
+ 
+ seek :: InitOptions -> CommandSeek
+ seek = commandAction . start
+diff --git a/Utility/HumanTime.hs b/Utility/HumanTime.hs
+index 01fbeacfb..d2e70f332 100644
+--- a/Utility/HumanTime.hs
++++ b/Utility/HumanTime.hs
+@@ -19,6 +19,7 @@ module Utility.HumanTime (
+ import Utility.PartialPrelude
+ import Utility.QuickCheck
+ 
++import Control.Monad.Fail as Fail ( MonadFail(..) )
+ import qualified Data.Map as M
+ import Data.Time.Clock
+ import Data.Time.Clock.POSIX (POSIXTime)
+@@ -44,7 +45,7 @@ daysToDuration :: Integer -> Duration
+ daysToDuration i = Duration $ i * dsecs
+ 
+ {- Parses a human-input time duration, of the form "5h", "1m", "5h1m", etc -}
+-parseDuration :: Monad m => String -> m Duration
++parseDuration :: MonadFail m => String -> m Duration
+ parseDuration = maybe parsefail (return . Duration) . go 0
+   where
+ 	go n [] = return n
+@@ -55,7 +56,7 @@ parseDuration = maybe parsefail (return . Duration) . go 0
+ 				u <- M.lookup c unitmap
+ 				go (n + num * u) rest
+ 			_ -> return $ n + num
+-	parsefail = fail "duration parse error; expected eg \"5m\" or \"1h5m\""
++	parsefail = Fail.fail "duration parse error; expected eg \"5m\" or \"1h5m\""
+ 
+ fromDuration :: Duration -> String
+ fromDuration Duration { durationSeconds = d }
+-- 
+2.25.1
+