The build is unreachable.

Build log

> /tmp/stackage-build2454$ stack unpack app-settings-0.2.0.12@sha256:7d797fbd8e71338ee4e16aa481d2676605dc926c5fbe74ac4a0238c2b5fcd4a1
Unpacked app-settings-0.2.0.12 to /tmp/stackage-build2454/app-settings-0.2.0.12/
> /tmp/stackage-build2454/app-settings-0.2.0.12$ 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-build2454/app-settings-0.2.0.12$ ./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/app-settings-0.2.0.12 --htmldir=/home/circleci/project/builds/nightly/doc/app-settings-0.2.0.12 --haddockdir=/home/circleci/project/builds/nightly/doc/app-settings-0.2.0.12
Configuring app-settings-0.2.0.12...
> /tmp/stackage-build2454/app-settings-0.2.0.12$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/app-settings-0.2.0.12$ ./Setup build
Preprocessing library for app-settings-0.2.0.12..
Building library for app-settings-0.2.0.12..
[1 of 3] Compiling Data.Serialization ( Data/Serialization.hs, dist/build/Data/Serialization.o )
[2 of 3] Compiling Data.AppSettingsInternal ( Data/AppSettingsInternal.hs, dist/build/Data/AppSettingsInternal.o )
[3 of 3] Compiling Data.AppSettings ( Data/AppSettings.hs, dist/build/Data/AppSettings.o )

Data/AppSettings.hs:22:1: 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()
   |
22 | import Control.Applicative
   | ^^^^^^^^^^^^^^^^^^^^^^^^^^
> /tmp/stackage-build2454/app-settings-0.2.0.12$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/app-settings-0.2.0.12$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181117/app-settings-0.2.0.12-G3q1NLB0Jqb3V97I6k208C
> /tmp/stackage-build2454/app-settings-0.2.0.12$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/app-settings-0.2.0.12$ ./Setup register
Registering library for app-settings-0.2.0.12..