The build is unreachable.
Build log
> /tmp/stackage-build2454$ stack unpack leapseconds-announced-2017.1.0.1@sha256:245cdcabb8060cab1bdb19d3a4e253a946db69c1ae636923348c7d3cbd05495b
Unpacked leapseconds-announced-2017.1.0.1 to /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1/
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ 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-build2454/leapseconds-announced-2017.1.0.1$ ./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/leapseconds-announced-2017.1.0.1 --htmldir=/home/circleci/project/builds/nightly/doc/leapseconds-announced-2017.1.0.1 --haddockdir=/home/circleci/project/builds/nightly/doc/leapseconds-announced-2017.1.0.1
Configuring leapseconds-announced-2017.1.0.1...
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ ./Setup build
Preprocessing library for leapseconds-announced-2017.1.0.1..
Building library for leapseconds-announced-2017.1.0.1..
[1 of 1] Compiling Data.Time.Clock.AnnouncedLeapSeconds ( src/Data/Time/Clock/AnnouncedLeapSeconds.hs, dist/build/Data/Time/Clock/AnnouncedLeapSeconds.o )
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181122/leapseconds-announced-2017.1.0.1-4RhJkxI7Npz5i8OQh2TjG7
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/leapseconds-announced-2017.1.0.1$ ./Setup register
Registering library for leapseconds-announced-2017.1.0.1..