Remove unused packages from happy executable

Author: andreasabel

.github/workflows/haskell-ci.yml

@@ -227,6 +227,10 @@ jobs:
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods -Werror=missing-fields" >> cabal.project ; fi
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "package happy" >> cabal.project ; fi
           if [ $((HCNUMVER >= 80200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods -Werror=missing-fields" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "package happy-lib" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "package happy" >> cabal.project ; fi
+          if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
           cat >> cabal.project <<EOF
           EOF
           $HCPKG list --simple-output --names-only | perl -ne 'for (split /\s+/) { print "constraints: any.$_ installed\n" unless /^(happy|happy-lib|mtl|transformers)$/; }' >> cabal.project.local

cabal.haskell-ci

@@ -1,6 +1,6 @@
 branches: master
 error-incomplete-patterns: False
-error-unused-packages: False
+error-unused-packages: >=9
 
 -- Specify 'constraint: ... installed' packages
 installed: +all -transformers -mtl

happy.cabal

@@ -141,9 +141,6 @@ executable happy
   main-is: Main.lhs
 
   build-depends: base >= 4.9 && < 5,
-                 array,
-                 containers >= 0.4.2,
-                 mtl >= 2.2.1,
                  happy-lib == 2.1.7
 
   default-language: Haskell98