From 74704110ca0eb6760a6e133ac88133a590d4ef8f Mon Sep 17 00:00:00 2001
From: Daniel Gröber <dxld@darkboxed.org>
Date: Wed, 30 Jan 2019 20:58:02 +0100
Subject: Fix ghc-pkg guessing logic when using v2-install

---
 lib/Distribution/Helper.hs                          | 12 +++++++-----
 src/CabalHelper/Compiletime/Program/CabalInstall.hs |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/lib/Distribution/Helper.hs b/lib/Distribution/Helper.hs
index 664ff01..ca5c1b1 100644
--- a/lib/Distribution/Helper.hs
+++ b/lib/Distribution/Helper.hs
@@ -588,13 +588,15 @@ withProgs impl QueryEnv{..} f = do
   where
     -- | Determine ghc-pkg path from ghc path
     guessCompProgramPaths :: Verbose => CompPrograms -> IO CompPrograms
+    guessCompProgramPaths progs
+      | same ghcProgram progs dprogs = return progs
     guessCompProgramPaths progs = do
         let v | ?verbose  = deafening
               | otherwise = silent
             mGhcPath0    | same ghcProgram progs dprogs = Nothing
-                        | otherwise = Just $ ghcProgram progs
+                         | otherwise = Just $ ghcProgram progs
             mGhcPkgPath0 | same ghcPkgProgram progs dprogs = Nothing
-                        | otherwise = Just $ ghcPkgProgram progs
+                         | otherwise = Just $ ghcPkgProgram progs
         (_compiler, _mplatform, progdb)
             <- GHC.configure
                   v
@@ -608,9 +610,9 @@ withProgs impl QueryEnv{..} f = do
           { ghcProgram    = fromMaybe (ghcProgram progs) mghcPath1
           , ghcPkgProgram = fromMaybe (ghcProgram progs) mghcPkgPath1
           }
-      where
-        same f o o'  = f o == f o'
-        dprogs = defaultCompPrograms
+
+    same f o o'  = f o == f o'
+    dprogs = defaultCompPrograms
 
 getHelperExe
     :: ProjInfo pt -> QueryEnvI c pt -> IO FilePath
diff --git a/src/CabalHelper/Compiletime/Program/CabalInstall.hs b/src/CabalHelper/Compiletime/Program/CabalInstall.hs
index 6b6d401..3f87215 100644
--- a/src/CabalHelper/Compiletime/Program/CabalInstall.hs
+++ b/src/CabalHelper/Compiletime/Program/CabalInstall.hs
@@ -228,7 +228,7 @@ cabalV2WithGHCProgOpts :: Progs => [String]
 cabalV2WithGHCProgOpts = concat
   [ [ "--with-compiler=" ++ ghcProgram ?cprogs ]
   , if ghcPkgProgram ?cprogs /= ghcPkgProgram defaultCompPrograms
-      then error "cabalV2WithGHCProgOpts: ghc-pkg path was changed from default but cabal v2-install does not support passing --with-ghc-pkg!"
+      then [ "--with-hc-pkg=" ++ ghcPkgProgram ?cprogs ]
       else []
   ]
 
-- 
cgit v1.2.3