The build is unreachable.

Build log

> /tmp/stackage-build2456$ stack unpack countable-1.0@sha256:965ba98037e9db0798cbc4270683c2cfde93ddc27c49b4634a3b24ba730dd4d5
Unpacked countable-1.0 to /tmp/stackage-build2456/countable-1.0/
> /tmp/stackage-build2456/countable-1.0$ 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-build2456/countable-1.0$ ./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/countable-1.0 --htmldir=/home/circleci/project/builds/nightly/doc/countable-1.0 --haddockdir=/home/circleci/project/builds/nightly/doc/countable-1.0
Configuring countable-1.0...
> /tmp/stackage-build2456/countable-1.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/countable-1.0$ ./Setup build
Preprocessing library for countable-1.0..
Building library for countable-1.0..
[1 of 4] Compiling Data.Countable   ( src/Data/Countable.hs, dist/build/Data/Countable.o )
[2 of 4] Compiling Data.Expression  ( src/Data/Expression.hs, dist/build/Data/Expression.o )
[3 of 4] Compiling Data.Searchable  ( src/Data/Searchable.hs, dist/build/Data/Searchable.o )
[4 of 4] Compiling Data.Empty       ( src/Data/Empty.hs, dist/build/Data/Empty.o )
> /tmp/stackage-build2456/countable-1.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/countable-1.0$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181116/countable-1.0-Ikq9tpbtETMFkSGyGJ63xt
> /tmp/stackage-build2456/countable-1.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/countable-1.0$ ./Setup register
Registering library for countable-1.0..