fix manage script

It now work with nixos-rebuild repl properly

nix/packages/by-name/manage/src/Main.hs

@@ -2,6 +2,7 @@
 {-# LANGUAGE LambdaCase #-}
 {-# LANGUAGE ViewPatterns #-}
 
+import Control.Monad
 import System.Environment
 import System.Exit
 import System.IO
@@ -22,18 +23,14 @@ main = do
       ) ->
         manageArgs `showHelpOr` do
           nixpkgs <- readNixpkgsPath
-          -- NOTE: It seems like nom is able to do some pty magic and can print out to terminal in real time.
-          -- I thought this would be blocking?
-          readProcessFriendly "nixos-rebuild" (action : nixosRebuildArgs nixpkgs host <> extraArgs) ""
-            >>= putStr
+          void $ readProcessFriendly "nixos-rebuild" (action : nixosRebuildArgs nixpkgs host <> extraArgs)
 
     ( "install" : host
       : (partitionArgs -> (manageArgs, extraArgs))
       ) ->
         manageArgs `showHelpOr` do
           nixpkgs <- readNixpkgsPath
-          readProcessFriendly "nixos-install" (nixosInstallArgs nixpkgs host <> extraArgs) ""
-            >>= putStr
+          void $ readProcessFriendly "nixos-install" (nixosInstallArgs nixpkgs host <> extraArgs)
 
     _ -> putStr help >> exitFailure
 
@@ -82,11 +79,18 @@ quote x = "\"" <> x <> "\""
 blueForeground :: String -> String
 blueForeground x = "\ESC[34m" <> x <> "\ESC[0m"
 
-readProcessFriendly :: String -> [String] -> String -> IO String
-readProcessFriendly x args stdin_ = do
+readProcessFriendly :: String -> [String] -> IO String
+readProcessFriendly cmdName args = do
   hPutStrLn stderr
-    $ "Executing: " <> (quote . blueForeground) (showCommandForUser x args)
-  readProcess x args stdin_
+    $ "Executing: " <> (quote . blueForeground) (showCommandForUser cmdName args)
+  (_, _, _, pid) <- createProcess
+      ( proc cmdName args
+      ) { std_in = UseHandle stdin
+        , std_out = UseHandle stdout
+        , std_err = UseHandle stderr
+        }
+  _ <- waitForProcess pid
+  pure ""
 
 readNixpkgsPath :: IO StorePath
 readNixpkgsPath =
@@ -96,6 +100,5 @@ readNixpkgsPath =
     , "-E"
     , "let sources = import ./npins; in sources.nixpkgs.outPath"
     ]
-    ""
   where
     clean = filter (\c -> c /= '\n' && c /= '"')