Try generating a license report

.config/project/github-ci.nix

@@ -130,6 +130,30 @@ in {
           }
         ];
       };
+      check-licenses = {
+        runs-on = "ubuntu-22.04";
+        steps = [
+          {uses = "actions/checkout@v4";}
+          {
+            ## TODO: Uses deprecated Node.js, see haskell-actions/setup#72
+            uses = "haskell-actions/setup@v2";
+            id = "setup-haskell-cabal";
+            "with" = {
+              ## NB: `cabal-plan` doesn’t yet support GHC 9.8.
+              ghc-version = "9.6.3";
+              cabal-version = pkgs.cabal-install.version;
+            };
+          }
+          {run = "cabal install cabal-plan -flicense-report";}
+          {
+            name = "check if licenses have changed";
+            run = ''
+              cabal-plan license-report all >docs/license-info.md
+              git diff --exit-code license-info.md
+            '';
+          }
+        ];
+      };
     };
   };
 }

core/src/Yaya/Fold.hs

@@ -1,3 +1,4 @@
+{-# LANGUAGE CPP #-}
 {-# LANGUAGE GADTs #-}
 {-# LANGUAGE Safe #-}
 
@@ -260,6 +261,7 @@ recursiveShowsPrec' showsFPrec = flip . cata $
       showString embedOperation . showString " " . showsFPrec f appPrec1
 
 -- | An implementation of `showsPrec` for any `Recursive` instance.
+#if MIN_VERSION_GLASGOW_HASKELL (8, 10, 0, 0)
 --
 -- >>> :{
 --   recursiveShowsPrec
@@ -278,6 +280,7 @@ recursiveShowsPrec' showsFPrec = flip . cata $
 --     ""
 -- :}
 -- "(embed (Both \"a\" (embed (Both \"b\" (embed Neither)))))"
+#endif
 --
 --  __NB__: Use `recursiveShowsPrec'` if you need to use a custom serialization
 --          function for @f@.