The build is unreachable.

Build log

> /tmp/stackage-build2456$ stack unpack sum-type-boilerplate-0.1.1@sha256:a993fd0faa7f31e58af3ae071ecbaea9a8cc8cb6095fc26e72c9450100560d1f
Unpacked sum-type-boilerplate-0.1.1 to /tmp/stackage-build2456/sum-type-boilerplate-0.1.1/
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ 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/sum-type-boilerplate-0.1.1$ ./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/sum-type-boilerplate-0.1.1 --htmldir=/home/circleci/project/builds/nightly/doc/sum-type-boilerplate-0.1.1 --haddockdir=/home/circleci/project/builds/nightly/doc/sum-type-boilerplate-0.1.1
Configuring sum-type-boilerplate-0.1.1...
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ ./Setup build
Preprocessing library for sum-type-boilerplate-0.1.1..
Building library for sum-type-boilerplate-0.1.1..
[1 of 1] Compiling SumTypes.TH      ( library/SumTypes/TH.hs, dist/build/SumTypes/TH.o )
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181117/sum-type-boilerplate-0.1.1-BVxY8L5VkySHXlfpnAk5sf
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/sum-type-boilerplate-0.1.1$ ./Setup register
Registering library for sum-type-boilerplate-0.1.1..