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authoralexwl <alexey.a.kiryushin@gmail.com>2018-10-08 02:40:18 +0300
committeralexwl <alexey.a.kiryushin@gmail.com>2018-10-08 02:40:18 +0300
commitf38daf67730fe31b865528eb972c619857e62a5c (patch)
tree093c30681686f834dfa4b39da119e230b19284e9 /vendor/cabal-helper-0.8.1.2/lib/Distribution
parent579a0f16c4f3ad2bcc8a283081d214fbe1ee3a59 (diff)
Update cabal-helper to version 0.8.1.2 that supports Cabal (>=1.14 && <1.26 || >=2.0 && <2.5)
Building cabal-helper-0.8.1.2 with Stack failed with 'Dependency cycle detected' error. It seems to be https://github.com/commercialhaskell/stack/issues/4265 Stack bug. As a temporary solution I added source code of cabal-helper package to vendor directory and commented out 'build-tool-depends: cabal-helper:cabal-helper-wrapper' line in the cabal-helper.cabal file.
Diffstat (limited to 'vendor/cabal-helper-0.8.1.2/lib/Distribution')
-rw-r--r--vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs589
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diff --git a/vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs b/vendor/cabal-helper-0.8.1.2/lib/Distribution/Helper.hs
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+-- cabal-helper: Simple interface to Cabal's configuration state
+-- Copyright (C) 2015-2018 Daniel Gröber <cabal-helper@dxld.at>
+--
+-- This program is free software: you can redistribute it and/or modify
+-- it under the terms of the GNU General Public License as published by
+-- the Free Software Foundation, either version 3 of the License, or
+-- (at your option) any later version.
+--
+-- This program is distributed in the hope that it will be useful,
+-- but WITHOUT ANY WARRANTY; without even the implied warranty of
+-- MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
+-- GNU General Public License for more details.
+--
+-- You should have received a copy of the GNU General Public License
+-- along with this program. If not, see <http://www.gnu.org/licenses/>.
+
+{-# LANGUAGE CPP, RecordWildCards, FlexibleContexts, ConstraintKinds,
+ GeneralizedNewtypeDeriving, DeriveDataTypeable, DeriveGeneric, DeriveFunctor,
+ NamedFieldPuns, OverloadedStrings
+ #-}
+
+{-|
+Module : Distribution.Helper
+License : GPL-3
+Maintainer : cabal-helper@dxld.at
+Portability : POSIX
+-}
+
+module Distribution.Helper (
+ -- * Running Queries
+ Query
+ , runQuery
+
+ -- * Queries against Cabal\'s on disk state
+
+ -- ** Package queries
+ , packageId
+ , packageDbStack
+ , packageFlags
+ , compilerVersion
+
+ , ghcMergedPkgOptions
+
+ -- ** cabal-install queries
+ , configFlags
+ , nonDefaultConfigFlags
+
+
+ -- ** Component queries
+ , ComponentQuery
+ , components
+
+ , ghcSrcOptions
+ , ghcPkgOptions
+ , ghcLangOptions
+ , ghcOptions
+ , sourceDirs
+ , entrypoints
+ , needsBuildOutput
+
+ -- * Query environment
+ , QueryEnv
+ , mkQueryEnv
+ , qeReadProcess
+ , qePrograms
+ , qeProjectDir
+ , qeDistDir
+ , qeCabalPkgDb
+ , qeCabalVer
+
+ , Programs(..)
+ , defaultPrograms
+
+
+ -- * Result types
+ , ChModuleName(..)
+ , ChComponentName(..)
+ , ChPkgDb(..)
+ , ChEntrypoint(..)
+ , NeedsBuildOutput(..)
+
+ -- * General information
+ , buildPlatform
+
+ -- * Stuff that cabal-install really should export
+ , Distribution.Helper.getSandboxPkgDb
+
+ -- * Managing @dist/@
+ , prepare
+ , reconfigure
+ , writeAutogenFiles
+
+ -- * $libexec related error handling
+ , LibexecNotFoundError(..)
+ , libexecNotFoundError
+
+ -- * Reexports
+ , module Data.Functor.Apply
+ ) where
+
+import Cabal.Plan
+import Control.Applicative
+import Control.Monad
+import Control.Monad.IO.Class
+import Control.Monad.State.Strict
+import Control.Monad.Reader
+import Control.Exception as E
+import Data.Char
+import Data.List
+import Data.Maybe
+import qualified Data.Map as Map
+import Data.Version
+import Data.Typeable
+import Data.Function
+import Data.Functor.Apply
+import Distribution.System (buildOS, OS(Windows))
+import System.Environment
+import System.FilePath hiding ((<.>))
+import qualified System.FilePath as FP
+import System.Directory
+import System.Process
+import System.IO.Unsafe
+import Text.Printf
+import GHC.Generics
+import Prelude
+
+import Paths_cabal_helper (getLibexecDir)
+import CabalHelper.Shared.InterfaceTypes
+import CabalHelper.Shared.Sandbox
+
+-- | Paths or names of various programs we need.
+data Programs = Programs {
+ -- | The path to the @cabal@ program.
+ cabalProgram :: FilePath,
+
+ -- | The path to the @ghc@ program.
+ ghcProgram :: FilePath,
+
+ -- | The path to the @ghc-pkg@ program. If
+ -- not changed it will be derived from the path to 'ghcProgram'.
+ ghcPkgProgram :: FilePath
+ } deriving (Eq, Ord, Show, Read, Generic, Typeable)
+
+-- | Default all programs to their unqualified names, i.e. they will be searched
+-- for on @PATH@.
+defaultPrograms :: Programs
+defaultPrograms = Programs "cabal" "ghc" "ghc-pkg"
+
+-- | Environment for running a 'Query'. The real constructor is not exposed,
+-- the field accessors are however. See below. Use the 'mkQueryEnv' smart
+-- constructor to construct one.
+data QueryEnv = QueryEnv {
+ -- | Field accessor for 'QueryEnv'. Defines how to start the cabal-helper
+ -- process. Useful if you need to capture stderr output from the helper.
+ qeReadProcess :: FilePath -> [String] -> String -> IO String,
+
+ -- | Field accessor for 'QueryEnv'.
+ qePrograms :: Programs,
+
+ -- | Field accessor for 'QueryEnv'. Defines path to the project directory,
+ -- i.e. a directory containing a @project.cabal@ file
+ qeProjectDir :: FilePath,
+
+
+ -- | Field accessor for 'QueryEnv'. Defines path to the @dist/@ directory,
+ -- /builddir/ in Cabal terminology.
+ qeDistDir :: FilePath,
+
+ -- | Field accessor for 'QueryEnv'. Defines where to look for the Cabal
+ -- library when linking the helper.
+ qeCabalPkgDb :: Maybe FilePath,
+
+ -- | Field accessor for 'QueryEnv'. If @dist/setup-config@ wasn\'t written
+ -- by this version of Cabal an error is thrown when running the query.
+ qeCabalVer :: Maybe Version
+ }
+
+-- | @mkQueryEnv projdir distdir@. Smart constructor for 'QueryEnv'.
+-- Sets fields 'qeProjectDir' and 'qeDistDir' to @projdir@ and @distdir@
+-- respectively and provides sensible defaults for the other fields.
+mkQueryEnv :: FilePath
+ -- ^ Path to the project directory, i.e. the directory containing a
+ -- @project.cabal@ file
+ -> FilePath
+ -- ^ Path to the @dist/@ directory, called /builddir/ in Cabal
+ -- terminology.
+ -> QueryEnv
+mkQueryEnv projdir distdir = QueryEnv {
+ qeReadProcess = readProcess
+ , qePrograms = defaultPrograms
+ , qeProjectDir = projdir
+ , qeDistDir = distdir
+ , qeCabalPkgDb = Nothing
+ , qeCabalVer = Nothing
+ }
+
+data SomeLocalBuildInfo = SomeLocalBuildInfo {
+ slbiPackageDbStack :: [ChPkgDb],
+ slbiPackageFlags :: [(String, Bool)],
+ slbiCompilerVersion :: (String, Version),
+
+ slbiGhcMergedPkgOptions :: [String],
+
+ slbiConfigFlags :: [(String, Bool)],
+ slbiNonDefaultConfigFlags :: [(String, Bool)],
+
+ slbiGhcSrcOptions :: [(ChComponentName, [String])],
+ slbiGhcPkgOptions :: [(ChComponentName, [String])],
+ slbiGhcLangOptions :: [(ChComponentName, [String])],
+ slbiGhcOptions :: [(ChComponentName, [String])],
+
+ slbiSourceDirs :: [(ChComponentName, [String])],
+ slbiEntrypoints :: [(ChComponentName, ChEntrypoint)],
+ slbiNeedsBuildOutput :: [(ChComponentName, NeedsBuildOutput)]
+ } deriving (Eq, Ord, Read, Show)
+
+-- | A lazy, cached, query against a package's Cabal configuration. Use
+-- 'runQuery' to execute it.
+newtype Query m a = Query { unQuery :: StateT (Maybe SomeLocalBuildInfo)
+ (ReaderT QueryEnv m) a }
+ deriving (Functor, Applicative, Monad, MonadIO)
+
+instance MonadTrans Query where
+ lift = Query . lift . lift
+
+type MonadQuery m = ( MonadIO m
+ , MonadState (Maybe SomeLocalBuildInfo) m
+ , MonadReader QueryEnv m)
+
+-- | A 'Query' to run on all components of a package. Use 'components' to get a
+-- regular 'Query'.
+newtype ComponentQuery m a = ComponentQuery (Query m [(ChComponentName, a)])
+ deriving (Functor)
+
+instance (Functor m, Monad m) => Apply (ComponentQuery m) where
+ ComponentQuery flab <.> ComponentQuery fla =
+ ComponentQuery $ liftM2 go flab fla
+ where
+ go :: [(ChComponentName, a -> b)]
+ -> [(ChComponentName, a)]
+ -> [(ChComponentName, b)]
+ go lab la =
+ [ (cn, ab a)
+ | (cn, ab) <- lab
+ , (cn', a) <- la
+ , cn == cn'
+ ]
+
+run :: Monad m => QueryEnv -> Maybe SomeLocalBuildInfo -> Query m a -> m a
+run e s action = flip runReaderT e (flip evalStateT s (unQuery action))
+
+-- | @runQuery env query@. Run a 'Query' under a given 'QueryEnv'.
+runQuery :: Monad m
+ => QueryEnv
+ -> Query m a
+ -> m a
+runQuery qe action = run qe Nothing action
+
+getSlbi :: MonadQuery m => m SomeLocalBuildInfo
+getSlbi = do
+ s <- get
+ case s of
+ Nothing -> do
+ slbi <- getSomeConfigState
+ put (Just slbi)
+ return slbi
+ Just slbi -> return slbi
+
+-- | List of package databases to use.
+packageDbStack :: MonadIO m => Query m [ChPkgDb]
+
+-- | Like @ghcPkgOptions@ but for the whole package not just one component
+ghcMergedPkgOptions :: MonadIO m => Query m [String]
+
+-- | Flag definitions from cabal file
+packageFlags :: MonadIO m => Query m [(String, Bool)]
+
+-- | Flag assignments from setup-config
+configFlags :: MonadIO m => Query m [(String, Bool)]
+
+-- | Flag assignments from setup-config which differ from the default
+-- setting. This can also include flags which cabal decided to modify,
+-- i.e. don't rely on these being the flags set by the user directly.
+nonDefaultConfigFlags :: MonadIO m => Query m [(String, Bool)]
+
+-- | The version of GHC the project is configured to use
+compilerVersion :: MonadIO m => Query m (String, Version)
+
+-- | Package identifier, i.e. package name and version
+packageId :: MonadIO m => Query m (String, Version)
+
+-- | Run a ComponentQuery on all components of the package.
+components :: Monad m => ComponentQuery m (ChComponentName -> b) -> Query m [b]
+components (ComponentQuery sc) = map (\(cn, f) -> f cn) `liftM` sc
+
+-- | Modules or files Cabal would have the compiler build directly. Can be used
+-- to compute the home module closure for a component.
+entrypoints :: MonadIO m => ComponentQuery m ChEntrypoint
+
+-- | The component has a non-default module renaming, so needs build output ().
+needsBuildOutput :: MonadIO m => ComponentQuery m NeedsBuildOutput
+
+-- | A component's @source-dirs@ field, beware since if this is empty implicit
+-- behaviour in GHC kicks in.
+sourceDirs :: MonadIO m => ComponentQuery m [FilePath]
+
+-- | All options Cabal would pass to GHC.
+ghcOptions :: MonadIO m => ComponentQuery m [String]
+
+-- | Only search path related GHC options.
+ghcSrcOptions :: MonadIO m => ComponentQuery m [String]
+
+-- | Only package related GHC options, sufficient for things don't need to
+-- access any home modules.
+ghcPkgOptions :: MonadIO m => ComponentQuery m [String]
+
+-- | Only language related options, i.e. @-XSomeExtension@
+ghcLangOptions :: MonadIO m => ComponentQuery m [String]
+
+packageId = Query $ getPackageId
+packageDbStack = Query $ slbiPackageDbStack `liftM` getSlbi
+packageFlags = Query $ slbiPackageFlags `liftM` getSlbi
+compilerVersion = Query $ slbiCompilerVersion `liftM` getSlbi
+ghcMergedPkgOptions = Query $ slbiGhcMergedPkgOptions `liftM` getSlbi
+configFlags = Query $ slbiConfigFlags `liftM` getSlbi
+nonDefaultConfigFlags = Query $ slbiNonDefaultConfigFlags `liftM` getSlbi
+
+ghcSrcOptions = ComponentQuery $ Query $ slbiGhcSrcOptions `liftM` getSlbi
+ghcPkgOptions = ComponentQuery $ Query $ slbiGhcPkgOptions `liftM` getSlbi
+ghcOptions = ComponentQuery $ Query $ slbiGhcOptions `liftM` getSlbi
+ghcLangOptions = ComponentQuery $ Query $ slbiGhcLangOptions `liftM` getSlbi
+sourceDirs = ComponentQuery $ Query $ slbiSourceDirs `liftM` getSlbi
+entrypoints = ComponentQuery $ Query $ slbiEntrypoints `liftM` getSlbi
+needsBuildOutput = ComponentQuery $ Query $ slbiNeedsBuildOutput `liftM` getSlbi
+
+-- | Run @cabal configure@
+reconfigure :: MonadIO m
+ => (FilePath -> [String] -> String -> IO String)
+ -> Programs -- ^ Program paths
+ -> [String] -- ^ Command line arguments to be passed to @cabal@
+ -> m ()
+reconfigure readProc progs cabalOpts = do
+ let progOpts =
+ [ "--with-ghc=" ++ ghcProgram progs ]
+ -- Only pass ghc-pkg if it was actually set otherwise we
+ -- might break cabal's guessing logic
+ ++ if ghcPkgProgram progs /= "ghc-pkg"
+ then [ "--with-ghc-pkg=" ++ ghcPkgProgram progs ]
+ else []
+ ++ cabalOpts
+ _ <- liftIO $ readProc (cabalProgram progs) ("configure":progOpts) ""
+ return ()
+
+readHelper :: (MonadIO m, MonadQuery m) => [String] -> m [Maybe ChResponse]
+readHelper args = ask >>= \qe -> liftIO $ do
+ out <- either error id <$> invokeHelper qe args
+ let res = read out
+ liftIO $ evaluate res `E.catch` \se@(SomeException _) -> do
+ md <- lookupEnv' "CABAL_HELPER_DEBUG"
+ let msg = "readHelper: exception: '" ++ show se ++ "'"
+ error $ msg ++ case md of
+ Nothing -> ", for more information set the environment variable CABAL_HELPER_DEBUG"
+ Just _ -> ", output: '"++ out ++"'"
+
+invokeHelper :: QueryEnv -> [String] -> IO (Either String String)
+invokeHelper QueryEnv {..} args = do
+ let progArgs = [ "--with-ghc=" ++ ghcProgram qePrograms
+ , "--with-ghc-pkg=" ++ ghcPkgProgram qePrograms
+ , "--with-cabal=" ++ cabalProgram qePrograms
+ ]
+ exe <- findLibexecExe
+ let args' = progArgs ++ "v1-style":qeProjectDir:qeDistDir:args
+ out <- qeReadProcess exe args' ""
+ (Right <$> evaluate out) `E.catch` \(SomeException _) ->
+ return $ Left $ concat
+ ["invokeHelper", ": ", exe, " "
+ , intercalate " " (map show args')
+ , " failed"
+ ]
+
+getPackageId :: MonadQuery m => m (String, Version)
+getPackageId = ask >>= \QueryEnv {..} -> do
+ [ Just (ChResponseVersion pkgName pkgVer) ] <- readHelper [ "package-id" ]
+ return (pkgName, pkgVer)
+
+getSomeConfigState :: MonadQuery m => m SomeLocalBuildInfo
+getSomeConfigState = ask >>= \QueryEnv {..} -> do
+ res <- readHelper
+ [ "package-db-stack"
+ , "flags"
+ , "compiler-version"
+
+ , "ghc-merged-pkg-options"
+
+ , "config-flags"
+ , "non-default-config-flags"
+
+ , "ghc-src-options"
+ , "ghc-pkg-options"
+ , "ghc-lang-options"
+ , "ghc-options"
+
+ , "source-dirs"
+ , "entrypoints"
+ , "needs-build-output"
+ ]
+ let [ Just (ChResponsePkgDbs slbiPackageDbStack),
+ Just (ChResponseFlags slbiPackageFlags),
+ Just (ChResponseVersion comp compVer),
+
+ Just (ChResponseList slbiGhcMergedPkgOptions),
+
+ Just (ChResponseFlags slbiConfigFlags),
+ Just (ChResponseFlags slbiNonDefaultConfigFlags),
+
+ Just (ChResponseCompList slbiGhcSrcOptions),
+ Just (ChResponseCompList slbiGhcPkgOptions),
+ Just (ChResponseCompList slbiGhcLangOptions),
+ Just (ChResponseCompList slbiGhcOptions),
+
+ Just (ChResponseCompList slbiSourceDirs),
+ Just (ChResponseEntrypoints slbiEntrypoints),
+ Just (ChResponseNeedsBuild slbiNeedsBuildOutput)
+ ] = res
+ slbiCompilerVersion = (comp, compVer)
+ return $ SomeLocalBuildInfo {..}
+
+
+-- | Make sure the appropriate helper executable for the given project is
+-- installed and ready to run queries.
+prepare :: MonadIO m => QueryEnv -> m ()
+prepare qe =
+ liftIO $ void $ invokeHelper qe []
+
+-- | Create @cabal_macros.h@ and @Paths_\<pkg\>@ possibly other generated files
+-- in the usual place.
+writeAutogenFiles :: MonadIO m => QueryEnv -> m ()
+writeAutogenFiles qe =
+ liftIO $ void $ invokeHelper qe ["write-autogen-files"]
+
+-- | Get the path to the sandbox package-db in a project
+getSandboxPkgDb :: (FilePath -> [String] -> String -> IO String)
+ -> String
+ -- ^ Cabal build platform, i.e. @buildPlatform@
+ -> Version
+ -- ^ GHC version (@cProjectVersion@ is your friend)
+ -> IO (Maybe FilePath)
+getSandboxPkgDb readProc =
+ CabalHelper.Shared.Sandbox.getSandboxPkgDb $ unsafePerformIO $ buildPlatform readProc
+
+buildPlatform :: (FilePath -> [String] -> String -> IO String) -> IO String
+buildPlatform readProc = do
+ exe <- findLibexecExe
+ CabalHelper.Shared.Sandbox.dropWhileEnd isSpace <$> readProc exe ["print-build-platform"] ""
+
+-- | This exception is thrown by all 'runQuery' functions if the internal
+-- wrapper executable cannot be found. You may catch this and present the user
+-- an appropriate error message however the default is to print
+-- 'libexecNotFoundError'.
+data LibexecNotFoundError = LibexecNotFoundError String FilePath
+ deriving (Typeable)
+instance Exception LibexecNotFoundError
+instance Show LibexecNotFoundError where
+ show (LibexecNotFoundError exe dir) =
+ libexecNotFoundError exe dir "https://github.com/DanielG/cabal-helper/issues"
+
+findLibexecExe :: IO FilePath
+findLibexecExe = do
+ libexecdir <- getLibexecDir
+ let exeName = "cabal-helper-wrapper"
+ exe = libexecdir </> exeName FP.<.> exeExtension'
+
+ exists <- doesFileExist exe
+
+ if exists
+ then return exe
+ else do
+ mdir <- tryFindCabalHelperTreeDistDir
+ dir <- case mdir of
+ Nothing ->
+ throwIO $ LibexecNotFoundError exeName libexecdir
+ Just dir ->
+ return dir
+
+ return $ dir </> "build" </> exeName </> exeName
+
+findPlanJson :: FilePath -> IO (Maybe FilePath)
+findPlanJson base =
+ findFile (map (</> "cache") $ parents base) "plan.json"
+
+parents :: FilePath -> [FilePath]
+parents path = takeWhile (not . (`elem` ["", "."]) . dropDrive) dirs
+ where dirs = iterate takeDirectory path
+
+data DistDir = DistDir { ddType :: DistDirType, unDistDir :: FilePath }
+ deriving (Eq, Ord, Read, Show)
+data DistDirType = NewBuildDist | OldBuildDist
+ deriving (Eq, Ord, Read, Show)
+
+tryFindCabalHelperTreeDistDir :: IO (Maybe FilePath)
+tryFindCabalHelperTreeDistDir = do
+ exe <- canonicalizePath =<< getExecutablePath'
+ mplan <- findPlanJson exe
+ let mdistdir = takeDirectory . takeDirectory <$> mplan
+ cwd <- getCurrentDirectory
+
+ let candidates = sortBy (compare `on` ddType) $ concat
+ [ maybeToList $ DistDir NewBuildDist <$> mdistdir
+ , [ DistDir OldBuildDist $ (!!3) $ iterate takeDirectory exe ]
+ , if takeFileName exe == "ghc" -- we're probably in ghci; try CWD
+ then [ DistDir NewBuildDist $ cwd </> "dist-newstyle"
+ , DistDir NewBuildDist $ cwd </> "dist"
+ , DistDir OldBuildDist $ cwd </> "dist"
+ ]
+ else []
+ ]
+
+ distdirs
+ <- filterM isDistDir candidates
+ >>= mapM toOldBuildDistDir
+
+ return $ fmap unDistDir $ join $ listToMaybe $ distdirs
+
+isCabalHelperSourceDir :: FilePath -> IO Bool
+isCabalHelperSourceDir dir =
+ doesFileExist $ dir </> "cabal-helper.cabal"
+
+isDistDir :: DistDir -> IO Bool
+isDistDir (DistDir NewBuildDist dir) =
+ doesFileExist (dir </> "cache" </> "plan.json")
+isDistDir (DistDir OldBuildDist dir) =
+ doesFileExist (dir </> "setup-config")
+
+toOldBuildDistDir :: DistDir -> IO (Maybe DistDir)
+toOldBuildDistDir (DistDir NewBuildDist dir) = do
+ PlanJson {pjUnits} <- decodePlanJson $ dir </> "cache" </> "plan.json"
+ let munit = find isCabalHelperUnit $ Map.elems pjUnits
+ return $ DistDir OldBuildDist <$> join ((\Unit { uDistDir = mdistdir } -> mdistdir) <$> munit)
+ where
+ isCabalHelperUnit
+ Unit { uPId = PkgId (PkgName n) _
+ , uType = UnitTypeLocal
+ , uComps
+ } | n == "cabal-helper" &&
+ Map.member (CompNameExe "cabal-helper-wrapper") uComps
+ = True
+ isCabalHelperUnit _ = False
+toOldBuildDistDir x = return $ Just x
+
+
+
+
+libexecNotFoundError :: String -- ^ Name of the executable we were trying to
+ -- find
+ -> FilePath -- ^ Path to @$libexecdir@
+ -> String -- ^ URL the user will be directed towards to
+ -- report a bug.
+ -> String
+libexecNotFoundError exe dir reportBug = printf
+ ( "Could not find $libexecdir/%s\n"
+ ++"\n"
+ ++"If you are a cabal-helper developer you can set the environment variable\n"
+ ++"`cabal_helper_libexecdir' to override $libexecdir[1]. The following will\n"
+ ++"work in the cabal-helper source tree:\n"
+ ++"\n"
+ ++" $ export cabal_helper_libexecdir=$PWD/dist/build/%s\n"
+ ++"\n"
+ ++"[1]: %s\n"
+ ++"\n"
+ ++"If you don't know what I'm talking about something went wrong with your\n"
+ ++"installation. Please report this problem here:\n"
+ ++"\n"
+ ++" %s") exe exe dir reportBug
+
+getExecutablePath' :: IO FilePath
+getExecutablePath' =
+#if MIN_VERSION_base(4,6,0)
+ getExecutablePath
+#else
+ getProgName
+#endif
+
+lookupEnv' :: String -> IO (Maybe String)
+lookupEnv' k = lookup k <$> getEnvironment
+
+exeExtension' :: FilePath
+exeExtension'
+ | Windows <- buildOS = "exe"
+ | otherwise = ""