CI: Don't enable -Werror=unused-packages

Author: RyanGlScott

.github/workflows/haskell-ci.yml

@@ -228,14 +228,6 @@ jobs:
           if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods -Werror=missing-fields" >> cabal.project ; fi
           if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "package singletons-base-code-generator" >> cabal.project ; fi
           if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "    ghc-options: -Werror=missing-methods -Werror=missing-fields" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 90400)) -ne 0 ] ; then echo "package singletons" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 90400)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "package singletons-th" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "package singletons-base" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "package singletons-base-code-generator" >> cabal.project ; fi
-          if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "    ghc-options: -Werror=unused-packages" >> cabal.project ; fi
           if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "package singletons" >> cabal.project ; fi
           if [ $((HCNUMVER >= 90000)) -ne 0 ] ; then echo "    ghc-options: -Werror=incomplete-patterns -Werror=incomplete-uni-patterns" >> cabal.project ; fi
           if [ $((HCNUMVER >= 91200)) -ne 0 ] ; then echo "package singletons-th" >> cabal.project ; fi

cabal.haskell-ci

@@ -8,3 +8,6 @@ haddock-components:     libs
 installed:              +all -Cabal -Cabal-syntax
 -- Work around https://github.com/haskell-CI/haskell-ci/issues/766
 cabal-install-version:  3.14.1.1
+-- -Wunused-packages mistakenly flags some of singletons-base-test-suite's
+-- dependencies as unused.
+error-unused-packages:  False