The build is unreachable.
Build log
> /tmp/stackage-build2456$ stack unpack ghci-hexcalc-0.1.0.1@sha256:f2f05e6ee427794100b1571ed81d35e787841e0fd076d35852bed77c01da3ada
Unpacked ghci-hexcalc-0.1.0.1 to /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1/
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ 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/ghci-hexcalc-0.1.0.1$ ./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/ghci-hexcalc-0.1.0.1 --htmldir=/home/circleci/project/builds/nightly/doc/ghci-hexcalc-0.1.0.1 --haddockdir=/home/circleci/project/builds/nightly/doc/ghci-hexcalc-0.1.0.1
Configuring ghci-hexcalc-0.1.0.1...
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ ./Setup build
Preprocessing library for ghci-hexcalc-0.1.0.1..
Building library for ghci-hexcalc-0.1.0.1..
[1 of 1] Compiling Data.GHex ( src/Data/GHex.hs, dist/build/Data/GHex.o )
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181117/ghci-hexcalc-0.1.0.1-C8n99lHpdulHI5Ibqvca3p
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/ghci-hexcalc-0.1.0.1$ ./Setup register
Registering library for ghci-hexcalc-0.1.0.1..