Find build-tool installed programs before programs in path

We must consider the path to the installed build-tool before the path to
existing versions of the build tool in paths such as `extra-prog-path`
or in the system path.

This was previously fixed by #8972 but undone by #9527.

This also renames `appendProgramSearchPath` to
`prependProgramSearchPath` to describe correctly what that function
does.

Fixes #9756

Author: alt-romes

Cabal/src/Distribution/Simple/Configure.hs

@@ -85,7 +85,7 @@ import Distribution.Simple.PackageIndex (InstalledPackageIndex, lookupUnitId)
 import qualified Distribution.Simple.PackageIndex as PackageIndex
 import Distribution.Simple.PreProcess
 import Distribution.Simple.Program
-import Distribution.Simple.Program.Db (appendProgramSearchPath, lookupProgramByName)
+import Distribution.Simple.Program.Db (prependProgramSearchPath, modifyProgramSearchPath, lookupProgramByName)
 import Distribution.Simple.Setup.Common as Setup
 import Distribution.Simple.Setup.Config as Setup
 import Distribution.Simple.Utils
@@ -1236,13 +1236,14 @@ mkPromisedDepsSet comps = Map.fromList [((pn, CLibName ln), cid) | GivenComponen
 -- arguments.
 mkProgramDb :: ConfigFlags -> ProgramDb -> IO ProgramDb
 mkProgramDb cfg initialProgramDb = do
-  programDb <- appendProgramSearchPath (fromFlagOrDefault normal (configVerbosity cfg)) searchpath initialProgramDb
+  programDb <- modifyProgramSearchPath (getProgramSearchPath initialProgramDb ++) <$>
+                prependProgramSearchPath (fromFlagOrDefault normal (configVerbosity cfg)) searchpath initialProgramDb
   pure
     . userSpecifyArgss (configProgramArgs cfg)
     . userSpecifyPaths (configProgramPaths cfg)
     $ programDb
   where
-    searchpath = fromNubList $ configProgramPathExtra cfg
+    searchpath = fromNubList (configProgramPathExtra cfg) 
 
 -- Note. We try as much as possible to _prepend_ rather than postpend the extra-prog-path
 -- so that we can override the system path. However, in a v2-build, at this point, the "system" path

Cabal/src/Distribution/Simple/ConfigureScript.hs

@@ -169,7 +169,7 @@ runConfigureScript verbosity flags lbi = do
       maybeHostFlag = if hp == buildPlatform then [] else ["--host=" ++ show (pretty hp)]
       args' = configureFile' : args ++ ["CC=" ++ ccProgShort] ++ maybeHostFlag
       shProg = simpleProgram "sh"
-  progDb <- appendProgramSearchPath verbosity extraPath emptyProgramDb
+  progDb <- prependProgramSearchPath verbosity extraPath emptyProgramDb
   shConfiguredProg <-
     lookupProgram shProg
       `fmap` configureProgram verbosity shProg progDb

Cabal/src/Distribution/Simple/Program/Db.hs

@@ -34,7 +34,7 @@ module Distribution.Simple.Program.Db
     -- ** Query and manipulate the program db
   , addKnownProgram
   , addKnownPrograms
-  , appendProgramSearchPath
+  , prependProgramSearchPath
   , lookupKnownProgram
   , knownPrograms
   , getProgramSearchPath
@@ -225,12 +225,12 @@ modifyProgramSearchPath f db =
 -- | Modify the current 'ProgramSearchPath' used by the 'ProgramDb'
 -- by appending the provided extra paths. Also logs the added paths
 -- in info verbosity.
-appendProgramSearchPath
+prependProgramSearchPath
   :: Verbosity
   -> [FilePath]
   -> ProgramDb
   -> IO ProgramDb
-appendProgramSearchPath verbosity extraPaths db =
+prependProgramSearchPath verbosity extraPaths db =
   if not $ null extraPaths
     then do
       logExtraProgramSearchPath verbosity extraPaths

Cabal/src/Distribution/Simple/Program/Types.hs

@@ -97,7 +97,7 @@ type ProgArg = String
 -- We also use this path to set the environment when running child processes.
 --
 -- The @ProgramDb@ is created with a @ProgramSearchPath@ to which we
--- @appendProgramSearchPath@ to add the ones that come from cli flags and from
+-- @prependProgramSearchPath@ to add the ones that come from cli flags and from
 -- configurations. Then each of the programs that are configured in the db
 -- inherits the same path as part of @configureProgram@.
 type ProgramSearchPath = [ProgramSearchPathEntry]

cabal-install/src/Distribution/Client/CmdExec.hs

@@ -76,7 +76,7 @@ import Distribution.Simple.Program
   , simpleProgram
   )
 import Distribution.Simple.Program.Db
-  ( appendProgramSearchPath
+  ( prependProgramSearchPath
   , configuredPrograms
   , requireProgram
   )
@@ -168,7 +168,7 @@ execAction flags@NixStyleFlags{..} extraArgs globalFlags = do
   let extraPaths = pathAdditions baseCtx buildCtx
 
   programDb <-
-    appendProgramSearchPath
+    prependProgramSearchPath
       verbosity
       extraPaths
       . pkgConfigCompilerProgs

cabal-install/src/Distribution/Client/CmdInstall.hs

@@ -154,7 +154,7 @@ import Distribution.Simple.GHC
 import qualified Distribution.Simple.InstallDirs as InstallDirs
 import qualified Distribution.Simple.PackageIndex as PI
 import Distribution.Simple.Program.Db
-  ( appendProgramSearchPath
+  ( prependProgramSearchPath
   , defaultProgramDb
   , userSpecifyArgss
   , userSpecifyPaths
@@ -426,7 +426,7 @@ installAction flags@NixStyleFlags{extraFlags, configFlags, installFlags, project
     hcPath = flagToMaybe projectConfigHcPath
     hcPkg = flagToMaybe projectConfigHcPkg
 
-  configProgDb <- appendProgramSearchPath verbosity ((fromNubList packageConfigProgramPathExtra) ++ (fromNubList projectConfigProgPathExtra)) defaultProgramDb
+  configProgDb <- prependProgramSearchPath verbosity ((fromNubList packageConfigProgramPathExtra) ++ (fromNubList projectConfigProgPathExtra)) defaultProgramDb
   let
     -- ProgramDb with directly user specified paths
     preProgDb =

cabal-install/src/Distribution/Client/HttpUtils.hs

@@ -46,7 +46,7 @@ import Distribution.Simple.Program
 import Distribution.Simple.Program.Db
   ( ProgramDb
   , addKnownPrograms
-  , appendProgramSearchPath
+  , prependProgramSearchPath
   , configureAllKnownPrograms
   , emptyProgramDb
   , lookupProgram
@@ -408,7 +408,7 @@ configureTransport verbosity extraPath (Just name) =
 
   case find (\(name', _, _, _) -> name' == name) supportedTransports of
     Just (_, mprog, _tls, mkTrans) -> do
-      baseProgDb <- appendProgramSearchPath verbosity extraPath emptyProgramDb
+      baseProgDb <- prependProgramSearchPath verbosity extraPath emptyProgramDb
       progdb <- case mprog of
         Nothing -> return emptyProgramDb
         Just prog -> snd <$> requireProgram verbosity prog baseProgDb
@@ -424,7 +424,7 @@ configureTransport verbosity extraPath Nothing = do
 
   -- for all the transports except plain-http we need to try and find
   -- their external executable
-  baseProgDb <- appendProgramSearchPath verbosity extraPath emptyProgramDb
+  baseProgDb <- prependProgramSearchPath verbosity extraPath emptyProgramDb
   progdb <-
     configureAllKnownPrograms verbosity $
       addKnownPrograms

cabal-install/src/Distribution/Client/ProjectPlanning.hs

@@ -471,7 +471,7 @@ configureCompiler
       )
       $ do
         liftIO $ info verbosity "Compiler settings changed, reconfiguring..."
-        progdb <- liftIO $ appendProgramSearchPath verbosity (fromNubList packageConfigProgramPathExtra) defaultProgramDb
+        progdb <- liftIO $ prependProgramSearchPath verbosity (fromNubList packageConfigProgramPathExtra) defaultProgramDb
         let progdb' = userSpecifyPaths (Map.toList (getMapLast packageConfigProgramPaths)) progdb
         result@(_, _, progdb'') <-
           liftIO $

cabal-install/src/Distribution/Client/SetupWrapper.hs

@@ -89,7 +89,7 @@ import Distribution.Simple.Program
   , runDbProgram
   )
 import Distribution.Simple.Program.Db
-  ( appendProgramSearchPath
+  ( prependProgramSearchPath
   )
 import Distribution.Simple.Program.Find
   ( programSearchPathAsPATHVar
@@ -539,7 +539,7 @@ invoke verbosity path args options = do
     Nothing -> return ()
     Just logHandle -> info verbosity $ "Redirecting build log to " ++ show logHandle
 
-  progDb <- appendProgramSearchPath verbosity (useExtraPathEnv options) (useProgramDb options)
+  progDb <- prependProgramSearchPath verbosity (useExtraPathEnv options) (useProgramDb options)
 
   searchpath <-
     programSearchPathAsPATHVar $ getProgramSearchPath progDb

cabal-install/src/Distribution/Client/VCS.hs

@@ -62,7 +62,7 @@ import Distribution.Simple.Program
   , simpleProgram
   )
 import Distribution.Simple.Program.Db
-  ( appendProgramSearchPath
+  ( prependProgramSearchPath
   )
 import Distribution.Types.SourceRepo
   ( KnownRepoType (..)
@@ -206,7 +206,7 @@ configureVCS
   -> VCS Program
   -> IO (VCS ConfiguredProgram)
 configureVCS verbosity progPaths vcs@VCS{vcsProgram = prog} = do
-  progPath <- appendProgramSearchPath verbosity progPaths emptyProgramDb
+  progPath <- prependProgramSearchPath verbosity progPaths emptyProgramDb
   asVcsConfigured <$> requireProgram verbosity prog progPath
   where
     asVcsConfigured (prog', _) = vcs{vcsProgram = prog'}