Revert "Setup.hs: Better way of handling man page building."

This reverts commit ed061b91c8.

Setup.hs

@@ -4,7 +4,7 @@ import Distribution.Simple
 import Distribution.Simple.PreProcess
 import Distribution.Simple.Setup
          (copyDest, copyVerbosity, fromFlag, installVerbosity, BuildFlags(..))
-import Distribution.PackageDescription (PackageDescription(..), Executable(..), BuildInfo(..))
+import Distribution.PackageDescription (PackageDescription(..), Executable(..))
 import Distribution.Simple.LocalBuildInfo
          (LocalBuildInfo(..), absoluteInstallDirs)
 import Distribution.Verbosity ( Verbosity, silent )
@@ -19,19 +19,18 @@ import System.Exit
 main :: IO ()
 main = do
   defaultMainWithHooks $ simpleUserHooks {
-      buildHook = \pkgdescr ->
+      postBuild = makeManPages
-         (buildHook simpleUserHooks) pkgdescr{ executables =
-            [x | x <- executables pkgdescr,
-                 exeName x /= "make-pandoc-man-pages"] ++
-            [x{ buildInfo = (buildInfo x){ buildable = True } }
-               | x <- executables pkgdescr,
-                 exeName x == "make-pandoc-man-pages"] }
-    , postBuild = makeManPages
     , postCopy = \ _ flags pkg lbi ->
          installManpages pkg lbi (fromFlag $ copyVerbosity flags)
               (fromFlag $ copyDest flags)
     , postInst = \ _ flags pkg lbi ->
          installManpages pkg lbi (fromFlag $ installVerbosity flags) NoCopyDest
+    , copyHook = \pkgdescr ->
+         (copyHook simpleUserHooks) pkgdescr{ executables =
+            [x | x <- executables pkgdescr, exeName x /= "make-pandoc-man-pages"] }
+    , instHook = \pkgdescr ->
+         (instHook simpleUserHooks) pkgdescr{ executables =
+            [x | x <- executables pkgdescr, exeName x /= "make-pandoc-man-pages"] }
     , hookedPreProcessors = [ppBlobSuffixHandler]
     }
   exitWith ExitSuccess

pandoc.cabal

@@ -361,12 +361,10 @@ Executable pandoc
   Main-Is:         pandoc.hs
   Buildable:       True
 
+-- NOTE:  A trick in Setup.hs makes sure this won't be installed:
 Executable make-pandoc-man-pages
   Main-Is:       make-pandoc-man-pages.hs
   Hs-Source-Dirs: man
-  Buildable:     False
-  -- Setup.hs will make this look buildable in build phase,
-  -- but it won't be copied/installed
   Build-Depends: pandoc,
                  base >= 4.2 && < 5,
                  directory >= 1 && < 1.3,