(wip)

.github/workflows/haskell-ci.yml

@@ -210,6 +210,7 @@ jobs:
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "package X11-xft" >> cabal.project ; fi
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods" >> cabal.project ; fi
           cat >> cabal.project <<EOF
+          allow-newer:  setlocale:base
           package X11-xft
             flags: +pedantic
           EOF

X11-xft.cabal

@@ -34,6 +34,12 @@ library
   if flag(pedantic)
     ghc-options:      -Werror
 
+  -- Keep this in sync with the oldest version in 'tested-with'
+  if impl(ghc > 8.0.2)
+     -- don't treat unused-imports warning as errors, they may be necessary
+     -- for compatibility with older versions of base (or other deps)
+     ghc-options: -Wwarn=unused-imports
+
 source-repository head
   type:     git
   location: https://github.com/xmonad/X11-xft.git

cabal.project

@@ -1 +1,4 @@
 packages: ./
+
+allow-newer:
+  setlocale:base