From a7cccf2a7c5df8b26da9ea4fdcb6bac5ab3a3b75 Mon Sep 17 00:00:00 2001
From: Michael Snoyman <michael@snoyman.com>
Date: Mon, 29 Jun 2015 08:14:04 +0300
Subject: [PATCH] yesod devel support for stack

---
 yesod-bin/ChangeLog.md    |  5 +++++
 yesod-bin/Devel.hs        | 10 ++++++++--
 yesod-bin/main.hs         | 22 ++++++++++++++++++++--
 yesod-bin/yesod-bin.cabal |  2 +-
 4 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/yesod-bin/ChangeLog.md b/yesod-bin/ChangeLog.md
index ec00369c..79f44ca5 100644
--- a/yesod-bin/ChangeLog.md
+++ b/yesod-bin/ChangeLog.md
@@ -1,3 +1,8 @@
+## 1.4.11
+
+* Add support to `yesod devel` to detect and use `GHC_PACKAGE_PATH`. This makes
+  `yesod devel` compatible with `stack`, just run: `stack exec -- yesod devel`.
+
 ## 1.4.10
 
 * Scaffolding update
diff --git a/yesod-bin/Devel.hs b/yesod-bin/Devel.hs
index 717d9fe2..d58acfe1 100644
--- a/yesod-bin/Devel.hs
+++ b/yesod-bin/Devel.hs
@@ -115,6 +115,10 @@ data DevelOpts = DevelOpts
       , proxyTimeout :: Int
       , useReverseProxy :: Bool
       , terminateWith :: DevelTermOpt
+
+      -- Support for GHC_PACKAGE_PATH wrapping
+      , develConfigOpts :: [String]
+      , develEnv :: Maybe [(String, String)]
       } deriving (Show, Eq)
 
 getBuildDir :: DevelOpts -> String
@@ -353,8 +357,8 @@ configure opts extraArgs =
                                  , "--with-ghc=yesod-ghc-wrapper"
                                  , "--with-ar=yesod-ar-wrapper"
                                  , "--with-hc-pkg=ghc-pkg"
-                                 ] ++ extraArgs
-               )
+                                 ] ++ develConfigOpts opts ++ extraArgs
+               ) { env = develEnv opts }
 
 removeFileIfExists :: FilePath -> IO ()
 removeFileIfExists file = removeFile file `Ex.catch` handler
@@ -388,6 +392,8 @@ rebuildCabal :: DevelOpts -> IO Bool
 rebuildCabal opts = do
   putStrLn $ "Rebuilding application... (using " ++ cabalProgram opts ++ ")"
   checkExit =<< createProcess (proc (cabalProgram opts) args)
+        { env = develEnv opts
+        }
     where
       args | verbose opts = [ "build" ]
            | otherwise    = [ "build", "-v0" ]
diff --git a/yesod-bin/main.hs b/yesod-bin/main.hs
index b8169131..ae4bc012 100755
--- a/yesod-bin/main.hs
+++ b/yesod-bin/main.hs
@@ -5,7 +5,9 @@ import           Control.Monad          (unless)
 import           Data.Monoid
 import           Data.Version           (showVersion)
 import           Options.Applicative
+import           System.Environment     (getEnvironment)
 import           System.Exit            (ExitCode (ExitSuccess), exitWith)
+import           System.FilePath        (splitSearchPath)
 import           System.Process         (rawSystem)
 
 import           AddHandler             (addHandler)
@@ -108,7 +110,9 @@ main = do
     Version         -> putStrLn ("yesod-bin version: " ++ showVersion Paths_yesod_bin.version)
     AddHandler{..}  -> addHandler addHandlerRoute addHandlerPattern addHandlerMethods
     Test            -> cabalTest cabal
-    Devel{..}       -> let develOpts = DevelOpts
+    Devel{..}       ->do
+                       (configOpts, menv) <- handleGhcPackagePath
+                       let develOpts = DevelOpts
                              { isCabalDev   = optCabalPgm o == CabalDev
                              , forceCabal   = _develDisableApi
                              , verbose      = optVerbose o
@@ -121,14 +125,28 @@ main = do
                              , proxyTimeout = _proxyTimeout
                              , useReverseProxy = not _noReverseProxy
                              , terminateWith = if _interruptOnly then TerminateOnlyInterrupt else TerminateOnEnter
+                             , develConfigOpts = configOpts
+                             , develEnv = menv
                              }
-                       in devel develOpts develExtraArgs
+                       devel develOpts develExtraArgs
   where
     cabalTest cabal = do touch'
                          _ <- cabal ["configure", "--enable-tests", "-flibrary-only"]
                          _ <- cabal ["build"]
                          cabal ["test"]
 
+handleGhcPackagePath :: IO ([String], Maybe [(String, String)])
+handleGhcPackagePath = do
+    env <- getEnvironment
+    case lookup "GHC_PACKAGE_PATH" env of
+        Nothing -> return ([], Nothing)
+        Just gpp -> do
+            let opts = "--package-db=clear"
+                     : "--package-db=global"
+                     : map ("--package-db=" ++)
+                       (drop 1 $ reverse $ splitSearchPath gpp)
+            return (opts, Just $ filter (\(x, _) -> x /= "GHC_PACKAGE_PATH") env)
+
 optParser' :: ParserInfo Options
 optParser' = info (helper <*> optParser) ( fullDesc <> header "Yesod Web Framework command line utility" )
 
diff --git a/yesod-bin/yesod-bin.cabal b/yesod-bin/yesod-bin.cabal
index efe7c219..a457ed7b 100644
--- a/yesod-bin/yesod-bin.cabal
+++ b/yesod-bin/yesod-bin.cabal
@@ -1,5 +1,5 @@
 name:            yesod-bin
-version:         1.4.10
+version:         1.4.11
 license:         MIT
 license-file:    LICENSE
 author:          Michael Snoyman <michael@snoyman.com>