The build is unreachable.

Build log

> /tmp/stackage-build2453$ stack unpack pipes-4.3.9@sha256:4a152a9c9eb1e6c58e54360c541d960ba68c03579e097a47dd3ad38dec5a7c56
Unpacked pipes-4.3.9 to /tmp/stackage-build2453/pipes-4.3.9/
> /tmp/stackage-build2453/pipes-4.3.9$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
[1 of 1] Compiling Main             ( Setup.hs, Setup.o )
Linking Setup ...
> /tmp/stackage-build2453/pipes-4.3.9$ ./Setup configure --package-db=clear --package-db=global --package-db=/home/circleci/project/builds/nightly/pkgdb --libdir=/home/circleci/project/builds/nightly/lib --bindir=/home/circleci/project/builds/nightly/bin --datadir=/home/circleci/project/builds/nightly/share --libexecdir=/home/circleci/project/builds/nightly/libexec --sysconfdir=/home/circleci/project/builds/nightly/etc --docdir=/home/circleci/project/builds/nightly/doc/pipes-4.3.9 --htmldir=/home/circleci/project/builds/nightly/doc/pipes-4.3.9 --haddockdir=/home/circleci/project/builds/nightly/doc/pipes-4.3.9
Configuring pipes-4.3.9...
> /tmp/stackage-build2453/pipes-4.3.9$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2453/pipes-4.3.9$ ./Setup build
Preprocessing library for pipes-4.3.9..
Building library for pipes-4.3.9..
[1 of 6] Compiling Pipes.Internal   ( src/Pipes/Internal.hs, dist/build/Pipes/Internal.o )

src/Pipes/Internal.hs:48:1: warning: [-Wunused-imports]
    The import of ‘Control.Applicative’ is redundant
      except perhaps to import instances from ‘Control.Applicative’
    To import instances alone, use: import Control.Applicative()
   |
48 | import Control.Applicative (Alternative(..))
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^

src/Pipes/Internal.hs:52:1: warning: [-Wunused-imports]
    The import of ‘Data.Semigroup’ is redundant
      except perhaps to import instances from ‘Data.Semigroup’
    To import instances alone, use: import Data.Semigroup()
   |
52 | import Data.Semigroup
   | ^^^^^^^^^^^^^^^^^^^^^
[2 of 6] Compiling Pipes.Core       ( src/Pipes/Core.hs, dist/build/Pipes/Core.o )
[3 of 6] Compiling Pipes            ( src/Pipes.hs, dist/build/Pipes.o )

src/Pipes.hs:89:1: warning: [-Wunused-imports]
    The import of ‘Data.Semigroup’ is redundant
      except perhaps to import instances from ‘Data.Semigroup’
    To import instances alone, use: import Data.Semigroup()
   |
89 | import Data.Semigroup
   | ^^^^^^^^^^^^^^^^^^^^^
[4 of 6] Compiling Pipes.Lift       ( src/Pipes/Lift.hs, dist/build/Pipes/Lift.o )
[5 of 6] Compiling Pipes.Prelude    ( src/Pipes/Prelude.hs, dist/build/Pipes/Prelude.o )
[6 of 6] Compiling Pipes.Tutorial   ( src/Pipes/Tutorial.hs, dist/build/Pipes/Tutorial.o )
> /tmp/stackage-build2453/pipes-4.3.9$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2453/pipes-4.3.9$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181120/pipes-4.3.9-jhOruZmyuALMU1LNGcYGY
> /tmp/stackage-build2453/pipes-4.3.9$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2453/pipes-4.3.9$ ./Setup register
Registering library for pipes-4.3.9..