Add stack-install-cabal target

Author: jneira

install/src/Help.hs

@@ -10,6 +10,7 @@ import           Env
 import           Print
 import           Version
 import           BuildSystem
+import           Cabal
 
 printUsage :: Action ()
 printUsage = do
@@ -83,6 +84,7 @@ helpMessage versions@BuildableVersions {..} = do
       , stackTarget buildAllTarget
       , stackTarget buildDataTarget
       ]
+      ++ (if isRunFromStack then [stackTarget installCabalTarget] else [])
       ++ map (stackTarget . hieTarget) stackVersions
 
   cabalTargets =
@@ -136,6 +138,12 @@ cabalGhcsTarget =
   , "Show all GHC versions that can be installed via `cabal-build` and `cabal-build-all`."
   )
 
+installCabalTarget :: TargetDescription
+installCabalTarget =
+  ( "install-cabal"
+  , "Install the cabal executable. It will install the required minimum version for hie (currently " ++ versionToString requiredCabalVersion ++ ") if it isn't already present in $PATH"
+  )
+
 -- | Creates a message of the form "a, b, c and d", where a,b,c,d are GHC versions.
 -- If there is no GHC in the list of `hieVersions`
 allVersionMessage :: [String] -> String

install/src/HieInstall.hs

@@ -91,6 +91,7 @@ defaultMain = do
       )
 
     -- stack specific targets
+    when isRunFromStack (phony "stack-install-cabal" (need ["cabal"]))
     phony "stack-build"     (need (reverse $ map ("stack-hie-" ++) hieVersions))
     phony "stack-build-all" (need ["build-data", "build"])
     phony "stack-build-data" $ do