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...
Warning: The following packages are likely to be broken by the reinstalls:
parsec-3.1.13.0
Cabal-2.4.0.1
libiserv-8.6.1
ghci-8.6.1
ghc-8.6.1
ghc-boot-8.6.1
Continuing even though the plan contains dangerous reinstalls.
Starting     Diff-0.3.4
Starting     colour-2.3.4
Building     Diff-0.3.4
Building     colour-2.3.4
Completed    Diff-0.3.4
Starting     containers-0.5.11.0
Building     containers-0.5.11.0
Completed    colour-2.3.4
Starting     haskell-lexer-1.0.2
Building     haskell-lexer-1.0.2
Completed    haskell-lexer-1.0.2
Starting     integer-logarithms-1.0.2.2
Building     integer-logarithms-1.0.2.2
Completed    integer-logarithms-1.0.2.2
Starting     primitive-0.6.4.0
Building     primitive-0.6.4.0
Completed    primitive-0.6.4.0
Starting     transformers-compat-0.6.2
Completed    containers-0.5.11.0
Starting     ansi-terminal-0.8.2
Building     transformers-compat-0.6.2
Building     ansi-terminal-0.8.2
Completed    transformers-compat-0.6.2
Starting     pretty-show-1.6.16
Completed    ansi-terminal-0.8.2
Starting     vector-0.12.0.1
Building     pretty-show-1.6.16
Building     vector-0.12.0.1
Completed    pretty-show-1.6.16
Starting     binary-0.8.6.0
Building     binary-0.8.6.0
Completed    binary-0.8.6.0
Starting     ansi-wl-pprint-0.6.8.2
Building     ansi-wl-pprint-0.6.8.2
Completed    ansi-wl-pprint-0.6.8.2
Starting     text-1.2.3.1
Building     text-1.2.3.1
Completed    vector-0.12.0.1
Starting     optparse-applicative-0.14.3.0
Building     optparse-applicative-0.14.3.0
Completed    text-1.2.3.1
Starting     system-filepath-0.4.14
Completed    optparse-applicative-0.14.3.0
Starting     hashable-1.2.7.0
Building     hashable-1.2.7.0
Building     system-filepath-0.4.14
Completed    hashable-1.2.7.0
Starting     scientific-0.3.6.2
Building     scientific-0.3.6.2
Completed    system-filepath-0.4.14
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     nix-derivation-1.0.1
Building     nix-derivation-1.0.1
Completed    nix-derivation-1.0.1
Starting     nix-diff-1.0.5
Building     nix-diff-1.0.5
Completed    nix-diff-1.0.5