Tweak haddock-api.cabal for pending release

haddock-api/haddock-api.cabal

@@ -36,12 +36,12 @@ library
   default-language: Haskell2010
 
   -- this package typically supports only single major versions
-  build-depends: base            == 4.10.*
-               , Cabal           == 2.0.*
-               , ghc             == 8.2.*
-               , ghc-paths       == 0.1.*
-               , haddock-library >= 1.4.2 && < 1.5
-               , xhtml           == 3000.2.*
+  build-depends: base            ^>= 4.10.0
+               , Cabal           ^>= 2.0.0
+               , ghc             ^>= 8.2
+               , ghc-paths       ^>= 0.1.0.9
+               , haddock-library ^>= 1.4.4
+               , xhtml           ^>= 3000.2.2
 
   -- Versions for the dependencies below are transitively pinned by
   -- the non-reinstallable `ghc` package and hence need no version
@@ -58,6 +58,9 @@ library
   hs-source-dirs: src
 
   ghc-options: -funbox-strict-fields -Wall -fwarn-tabs -O2
+  ghc-options: -Wall
+  if impl(ghc >= 8.0)
+    ghc-options: -Wcompat -Wnoncanonical-monad-instances -Wnoncanonical-monadfail-instances
 
   exposed-modules:
     Documentation.Haddock
@@ -101,6 +104,9 @@ library
     Haddock.Convert
     Paths_haddock_api
 
+  autogen-modules:
+    Paths_haddock_api
+
 test-suite spec
   type:             exitcode-stdio-1.0
   default-language: Haskell2010
@@ -111,20 +117,27 @@ test-suite spec
       test
     , src
 
+  -- NB: We only use a small subset of lib:haddock-api here, which
+  --     explains why this component has a smaller build-depends set
   other-modules:
     Haddock.Backends.Hyperlinker.ParserSpec
     Haddock.Backends.Hyperlinker.Parser
     Haddock.Backends.Hyperlinker.Types
 
+  build-depends:
+      ghc         ^>= 8.2
+    , hspec       ^>= 2.4.4
+    , QuickCheck  ^>= 2.10
+
+  -- Versions for the dependencies below are transitively pinned by
+  -- the non-reinstallable `ghc` package and hence need no version
+  -- bounds
   build-depends:
       base
     , containers
-    , ghc
-    , hspec
-    , QuickCheck == 2.*
 
   build-tool-depends:
-    hspec-discover:hspec-discover
+    hspec-discover:hspec-discover ^>= 2.4.4
 
 source-repository head
   type:     git