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     call-stack-0.1.0
Starting     colour-2.3.4
Building     call-stack-0.1.0
Building     colour-2.3.4
Completed    call-stack-0.1.0
Starting     erf-2.0.0.0
Building     erf-2.0.0.0
Completed    erf-2.0.0.0
Starting     extensible-exceptions-0.1.1.4
Building     extensible-exceptions-0.1.1.4
Completed    extensible-exceptions-0.1.1.4
Starting     hostname-1.0
Building     hostname-1.0
Completed    colour-2.3.4
Starting     old-locale-1.0.0.7
Building     old-locale-1.0.0.7
Completed    hostname-1.0
Starting     parsec3-numbers-0.1.0
Building     parsec3-numbers-0.1.0
Completed    old-locale-1.0.0.7
Starting     primitive-0.6.4.0
Building     primitive-0.6.4.0
Completed    parsec3-numbers-0.1.0
Starting     random-1.1
Building     random-1.1
Completed    random-1.1
Starting     regex-base-0.93.2
Building     regex-base-0.93.2
Completed    regex-base-0.93.2
Starting     xml-1.3.14
Building     xml-1.3.14
Completed    xml-1.3.14
Starting     HUnit-1.6.0.0
Completed    primitive-0.6.4.0
Starting     ansi-terminal-0.8.2
Building     HUnit-1.6.0.0
Building     ansi-terminal-0.8.2
Completed    HUnit-1.6.0.0
Starting     regex-posix-0.95.2
Building     regex-posix-0.95.2
Completed    ansi-terminal-0.8.2
Starting     tf-random-0.5
Building     tf-random-0.5
Completed    tf-random-0.5
Starting     ansi-wl-pprint-0.6.8.2
Completed    regex-posix-0.95.2
Starting     QuickCheck-2.12.6.1
Building     ansi-wl-pprint-0.6.8.2
Building     QuickCheck-2.12.6.1
Completed    ansi-wl-pprint-0.6.8.2
Starting     test-framework-0.8.2.0
Building     test-framework-0.8.2.0
Completed    test-framework-0.8.2.0
Starting     test-framework-hunit-0.3.0.2
Building     test-framework-hunit-0.3.0.2
Completed    test-framework-hunit-0.3.0.2
Completed    QuickCheck-2.12.6.1
Starting     test-framework-quickcheck2-0.3.0.5
Building     test-framework-quickcheck2-0.3.0.5
Completed    test-framework-quickcheck2-0.3.0.5
Starting     fptest-0.2.3.0
Building     fptest-0.2.3.0
Failed to install fptest-0.2.3.0
Build log ( /home/builder/.cabal/logs/ghc-8.6.1/fptest-0.2.3.0-8bW6Y6Tewcl29fEPuBhuvB.log ):
cabal: Entering directory '/tmp/cabal-tmp-17137/fptest-0.2.3.0'
Configuring fptest-0.2.3.0...
Preprocessing executable 'qtrial' for fptest-0.2.3.0..
Building executable 'qtrial' for fptest-0.2.3.0..
[1 of 1] Compiling Main             ( src/QTrial.hs, dist/build/qtrial/qtrial-tmp/Main.o )

src/QTrial.hs:194:10: error:
    Duplicate instance declarations:
      instance Arbitrary CFloat -- Defined at src/QTrial.hs:194:10
      instance Arbitrary CFloat -- Defined in ‘Test.QuickCheck.Arbitrary’
    |
194 | instance Arbitrary CFloat where
    |          ^^^^^^^^^^^^^^^^

src/QTrial.hs:198:10: error:
    Duplicate instance declarations:
      instance Arbitrary CDouble -- Defined at src/QTrial.hs:198:10
      instance Arbitrary CDouble
        -- Defined in ‘Test.QuickCheck.Arbitrary’
    |
198 | instance Arbitrary CDouble where
    |          ^^^^^^^^^^^^^^^^^
cabal: Leaving directory '/tmp/cabal-tmp-17137/fptest-0.2.3.0'
cabal: Error: some packages failed to install:
fptest-0.2.3.0-8bW6Y6Tewcl29fEPuBhuvB failed during the building phase. The
exception was:
ExitFailure 1