## Summary Running `ghc-pkg list` seems to be quadratic in the number of packages. ``` > time ghc-pkg-9.10.3 -f ~/.local/state/cabal/store/ghc-9.10.3-415c/package.db/ list | wc -l 5886 ________________________________________________________ Executed in 4.33 secs fish external usr time 4.09 secs 0.55 millis 4.09 secs sys time 0.17 secs 1.02 millis 0.17 secs ``` A quick profile pointed to `closure` inefficient. ## Steps to reproduce AI Generated script to populate a package db with lots of stuff, so don't expect anything of it. ``` GHC="path/to/ghc" # or just `ghc` COMMON="--allow-newer=base,template-haskell,ghc,ghc-prim,bytestring,text,containers,deepseq,time,Cabal,Cabal-syntax,transformers,mtl,filepath,directory,process,ghc-bignum --constraint=hashable==1.4.7.0" run_batch() { local BATCH_NAME="$1" shift echo "=== Batch: $BATCH_NAME ===" for FLAVOR in \ "" \ "--enable-profiling --enable-library-profiling" \ "--enable-executable-dynamic --enable-shared" \ "--enable-library-profiling --enable-profiling --enable-shared" \ "--enable-debug-info=2" \ "--disable-optimization" \ "--ghc-options=-O2 --ghc-options=-fexpose-all-unfoldings"; do cabal install -w "$GHC" $COMMON $FLAVOR "$@" || echo " skip flavor: $FLAVOR" done } run_batch "core" \ text bytestring containers unordered-containers vector \ hashable scientific \ mtl transformers async stm run_batch "parsing" \ attoparsec megaparsec parsec optparse-applicative \ aeson yaml cassava aeson-pretty run_batch "web-core" \ network network-uri http-types http2 websockets \ http-client http-client-tls wai warp wai-extra \ req http-conduit run_batch "streaming" \ conduit pipes streaming run_batch "servant" \ servant servant-server servant-client \ servant-swagger swagger2 openapi3 run_batch "lenses" \ lens generic-lens generic-optics \ microlens-platform optics optics-th lens-aeson run_batch "fp-extras" \ free recursion-schemes profunctors comonad \ these semialign witherable extra safe split \ fgl algebraic-graphs run_batch "testing" \ tasty tasty-hunit tasty-quickcheck hspec QuickCheck hedgehog \ criterion gauge tasty-bench weigh run_batch "crypto-tls" \ cryptonite cryptohash-sha256 x509 x509-store tls connection run_batch "db" \ persistent persistent-sqlite esqueleto \ postgresql-simple postgresql-libpq mysql-simple sqlite-simple \ acid-state safecopy run_batch "misc" \ random uuid time process typed-process shake \ blaze-html lucid clay shakespeare \ inline-c language-c language-javascript run_batch "parallel" \ parallel monad-par massiv repa run_batch "cabal-libs" \ cabal-install-solver Cabal Cabal-syntax run_batch "haskell-meta" \ haskell-src-exts haskell-src-meta hint run_batch "pandoc" \ pandoc pandoc-types texmath skylighting skylighting-core citeproc run_batch "diagrams" \ diagrams diagrams-lib diagrams-svg diagrams-contrib \ gloss Chart Chart-diagrams run_batch "amazonka" \ amazonka amazonka-s3 amazonka-ec2 amazonka-dynamodb run_batch "web-frameworks" \ hakyll yesod yesod-core yesod-form yesod-auth run_batch "hls" \ ghcide hls-plugin-api run_batch "dhall" \ dhall ``` Then run the appropriate `ghc-pkg` invocation once more than 1000 packages are installed. ## Expected behavior Should be faster :) ## Environment * GHC version used: 9.10.3 and HEAD 38b76b2f1d918f10d2f9d3e57bd0459dfe671d4f Optional: * Operating System: arch linux * System Architecture: x86_64