Here's what my stack.yaml looks like: dependencies: - base >= 4.7 && < 5 - HTTP >= 4000.4.1 - integer-conversion >=0.1 - text-iso8601 >=0.1 - aeson >= 2.2.0.0 - lens-aeson >= 1.2.3 - lens >= 5.2.3 And here's what happens, right at the very end: aeson > [30 of 30] Compiling Data.Aeson.TH aeson > aeson > /tmp/stack-93f87a2c6282bdb6/aeson-2.2.0.0/src/Data/Aeson/TH.hs:1417:26: error: aeson > Not in scope: aeson > data constructor ‘Language.Haskell.TH.Datatype.TypeData’ aeson > NB: the module ‘Language.Haskell.TH.Datatype’ does not export ‘TypeData’. aeson > Suggested fix: aeson > Perhaps use one of these: aeson > ‘Language.Haskell.TH.Datatype.Unpack’ (imported from Language.Haskell.TH.Datatype), aeson > ‘Language.Haskell.TH.Datatype.Lazy’ (imported from Language.Haskell.TH.Datatype), aeson > ‘Language.Haskell.TH.Datatype.Strict’ (imported from Language.Haskell.TH.Datatype) aeson > | aeson > 1417 | Language.Haskell.TH.Datatype.TypeData -> False aeson > | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^ Progress 54/56 Error: [S-7282] Stack failed to execute the build plan. While executing the build plan, Stack encountered the following errors: [S-7011] While building package aeson-2.2.0.0 (scroll up to its section to see the error) using: /home/goober/.stack/setup-exe-cache/x86_64-linux-tinfo6/Cabal-simple_SvXsv1f__3.8.1.0_ghc-9.4.6 --verbose=1 --builddir=.stack-work/dist/x86_64-linux-tinfo6/Cabal-3.8.1.0 build --ghc-options " -fdiagnostics-color=always"