Removed support for git versions older than 2.5.

This entirely removes Git.BuildVersion, which avoids the possibility that
git-annex will behave differently based on the version of git it was built
with, rather than the version it's used with.

Debian oldoldstable is the oldest version of git that git-annex needs to
support, since it's used in the amd64ancient build.

cabal configure will fail if the git version is too old.

Sponsored-by: Nicholas Golder-Manning

Build/Configure.hs

@@ -81,7 +81,7 @@ getGitVersion = go =<< getEnv "FORCE_GIT_VERSION"
 	go (Just s) = return $ Config "gitversion" $ StringConfig s
 	go Nothing = do
 		v <- Git.Version.installed
-		let oldestallowed = Git.Version.normalize "2.1"
+		let oldestallowed = Git.Version.normalize "2.5"
 		when (v < oldestallowed) $
 			error $ "installed git version " ++ show v ++ " is too old! (Need " ++ show oldestallowed ++ " or newer)"
 		return $ Config "gitversion" $ StringConfig $ show v

CHANGELOG

@@ -26,6 +26,7 @@ git-annex (10.20250722) UNRELEASED; urgency=medium
     for exporttree=yes/importtree=yes remotes.
   * Bump aws build dependency to 0.24.1.
   * stack.yaml: Update to lts-24.2.
+  * Removed support for git versions older than 2.5.
 
  -- Joey Hess <id@joeyh.name>  Wed, 30 Jul 2025 13:45:42 -0400
 

Command/Smudge.hs

@@ -19,7 +19,6 @@ import Annex.WorkTree
 import Logs.Smudge
 import Logs.Location
 import qualified Database.Keys
-import qualified Git.BuildVersion
 import Git.FilePath
 import Git.Types
 import Git.HashObject
@@ -97,15 +96,7 @@ clean file = do
 	Annex.BranchState.disableUpdate -- optimisation
 	b <- liftIO $ L.hGetContents stdin
 	let passthrough = liftIO $ L.hPut stdout b
-	-- Before git 2.5, failing to consume all stdin here would
-	-- cause a SIGPIPE and crash it.
-	-- Newer git catches the signal and stops sending, which is
-	-- much faster. (Also, git seems to forget to free memory
-	-- when sending the file, so the less we let it send, the
-	-- less memory it will waste.)
-	let discardreststdin = if Git.BuildVersion.older "2.5"
-		then L.length b `seq` return ()
-		else liftIO $ hClose stdin
+	let discardreststdin = liftIO $ hClose stdin
 	let emitpointer = liftIO . S.hPut stdout . formatPointer
 	clean' file (parseLinkTargetOrPointerLazy' b)
 		passthrough

Git/BuildVersion.hs

@@ -1,21 +0,0 @@
-{- git build version
- -
- - Copyright 2011 Joey Hess <id@joeyh.name>
- -
- - Licensed under the GNU AGPL version 3 or higher.
- -}
-
-module Git.BuildVersion where
-
-import Git.Version
-import qualified BuildInfo
-
-{- Using the version it was configured for avoids running git to check its
- - version, at the cost that upgrading git won't be noticed.
- - This is only acceptable because it's rare that git's version influences
- - code's behavior. -}
-buildVersion :: GitVersion
-buildVersion = normalize BuildInfo.gitversion
-
-older :: String -> Bool
-older n = buildVersion < normalize n 

Git/CatFile.hs

@@ -54,7 +54,6 @@ import Git.Types
 import Git.HashObject
 import qualified Git.LsTree as LsTree
 import qualified Utility.CoProcess as CoProcess
-import qualified Git.BuildVersion as BuildVersion
 import Utility.Tuple
 
 data CatFileHandle = CatFileHandle 
@@ -403,14 +402,10 @@ withCatFileStream
 withCatFileStream check repo reader = assertLocal repo $
 	bracketIO start stop $ \(c, hin, hout, _) -> reader c hin hout
   where
-	params = catMaybes
-		[ Just $ Param "cat-file"
-		, Just $ Param ("--batch" ++ (if check then "-check" else "") ++ "=" ++ batchFormat)
-		-- This option makes it faster, but is not present in
-		-- older versions of git.
-		, if BuildVersion.older "2.4.3"
-			then Nothing
-			else Just $ Param "--buffer"
+	params =
+		[ Param "cat-file"
+		, Param ("--batch" ++ (if check then "-check" else "") ++ "=" ++ batchFormat)
+		, Param "--buffer" -- makes it faster
 		]
 
 	start = do

git-annex.cabal

@@ -813,7 +813,6 @@ Executable git-annex
     Git
     Git.AutoCorrect
     Git.Branch
-    Git.BuildVersion
     Git.Bundle
     Git.CatFile
     Git.CheckAttr