Warning: The install command is a part of the legacy v1 style of cabal usage.

Please switch to using either the new project style and the new-install
command or the legacy v1-install alias as new-style projects will become the
default in the next version of cabal-install. Please file a bug if you cannot
replicate a working v1- use case with the new-style commands.

For more information, see: https://wiki.haskell.org/Cabal/NewBuild

Resolving dependencies...
Starting     fail-4.9.0.0
Starting     hashable-1.2.7.0
Building     hashable-1.2.7.0
Building     fail-4.9.0.0
Completed    fail-4.9.0.0
Starting     integer-logarithms-1.0.2.2
Building     integer-logarithms-1.0.2.2
Completed    integer-logarithms-1.0.2.2
Starting     prettyprinter-1.2.1
Building     prettyprinter-1.2.1
Completed    hashable-1.2.7.0
Starting     primitive-0.6.4.0
Building     primitive-0.6.4.0
Completed    prettyprinter-1.2.1
Starting     unordered-containers-0.2.9.0
Building     unordered-containers-0.2.9.0
Completed    primitive-0.6.4.0
Starting     scientific-0.3.6.2
Building     scientific-0.3.6.2
Completed    unordered-containers-0.2.9.0
Completed    scientific-0.3.6.2
Starting     attoparsec-0.13.2.2
Building     attoparsec-0.13.2.2
Completed    attoparsec-0.13.2.2
Starting     llvm-hs-pure-7.0.0
Building     llvm-hs-pure-7.0.0
Completed    llvm-hs-pure-7.0.0
Downloading  llvm-hs-pretty-0.6.0.0
Downloaded   llvm-hs-pretty-0.6.0.0
Starting     llvm-hs-pretty-0.6.0.0
Building     llvm-hs-pretty-0.6.0.0
Failed to install llvm-hs-pretty-0.6.0.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.1/llvm-hs-pretty-0.6.0.0-19sAiY17qpO9pZLG1N7KTc.log ):
cabal: Entering directory '/tmp/cabal-tmp-12064/llvm-hs-pretty-0.6.0.0'
Configuring llvm-hs-pretty-0.6.0.0...
Preprocessing library for llvm-hs-pretty-0.6.0.0..
Building library for llvm-hs-pretty-0.6.0.0..
[1 of 2] Compiling LLVM.Pretty      ( src/LLVM/Pretty.hs, dist/build/LLVM/Pretty.o )

src/LLVM/Pretty.hs:852:10: error:
    Not in scope: data constructor ‘None’
    |
852 |   pretty None = "CSK_None"
    |          ^^^^
cabal: Leaving directory '/tmp/cabal-tmp-12064/llvm-hs-pretty-0.6.0.0'
cabal: Error: some packages failed to install:
llvm-hs-pretty-0.6.0.0-19sAiY17qpO9pZLG1N7KTc failed during the building
phase. The exception was:
ExitFailure 1