Require ghc >= 8.6, base >= 4.12.

This allows us to get rid of the old custom prelude and
some crufty cpp.  But the primary reason for this is that
conduit has bumped its base lower bound to 4.12, making it
impossible for us to support lower base versions.

1 files changed, 13 insertions, 17 deletions

diff --git a/pandoc.cabal b/pandoc.cabal
index 3bda8e877..1b6f3a50a 100644
--- a/pandoc.cabal
+++ b/pandoc.cabal
@@ -409,31 +409,27 @@ flag trypandoc
 
 common common-options
   default-language: Haskell2010
-  build-depends:    base         >= 4.9 && < 5
+  build-depends:    base         >= 4.12 && < 5
   ghc-options:      -Wall -fno-warn-unused-do-bind
                     -Wincomplete-record-updates
                     -Wnoncanonical-monad-instances
+                    -Wcpp-undef
+                    -Wincomplete-uni-patterns
+                    -Widentities
+                    -Wpartial-fields
+                    -Wmissing-signatures
+                    -fhide-source-paths
+                    -- -Wmissing-export-lists
 
-  if impl(ghc < 8.6)
-    hs-source-dirs:   prelude
-    other-modules:    Prelude
-    build-depends:    base-compat >= 0.10.5
-    other-extensions: NoImplicitPrelude
+  if impl(ghc >= 8.10)
+    ghc-options:    -Wunused-packages
+
+  if impl(ghc >= 9.0)
+    ghc-options:    -Winvalid-haddock
 
   if os(windows)
     cpp-options:      -D_WINDOWS
 
-  -- Later:
-  -- -Wpartial-fields        (currently used in Powerpoint writer)
-  -- -Wmissing-export-lists  (currently some Odt modules violate this)
-  -- -Wredundant-constraints (problematic if we want to support older base)
-  if impl(ghc >= 8.2)
-    ghc-options:      -Wcpp-undef
-  if impl(ghc >= 8.4)
-    ghc-options:      -Wincomplete-uni-patterns
-                      -Widentities
-                      -fhide-source-paths
-
 common common-executable
   import:           common-options
   build-depends:    pandoc