The build is unreachable.

Build log

> /tmp/stackage-build2454$ stack unpack prefix-units-0.2.0@sha256:1f982a1c560cec0e9dec15db7ead90d8987253a22026e0571977631527e7e9d4
Populating index cache ...
Populated index cache.
Unpacked prefix-units-0.2.0 to /tmp/stackage-build2454/prefix-units-0.2.0/
> /tmp/stackage-build2454/prefix-units-0.2.0$ 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-build2454/prefix-units-0.2.0$ ./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/prefix-units-0.2.0 --htmldir=/home/circleci/project/builds/nightly/doc/prefix-units-0.2.0 --haddockdir=/home/circleci/project/builds/nightly/doc/prefix-units-0.2.0
Configuring prefix-units-0.2.0...
> /tmp/stackage-build2454/prefix-units-0.2.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/prefix-units-0.2.0$ ./Setup build
Preprocessing library for prefix-units-0.2.0..
Building library for prefix-units-0.2.0..
[1 of 2] Compiling Data.Prefix.Units.Compat ( Data/Prefix/Units/Compat.hs, dist/build/Data/Prefix/Units/Compat.o )
[2 of 2] Compiling Data.Prefix.Units ( Data/Prefix/Units.hs, dist/build/Data/Prefix/Units.o )
> /tmp/stackage-build2454/prefix-units-0.2.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/prefix-units-0.2.0$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181122/prefix-units-0.2.0-3wOc8AfSB3p9Y1IjQ7V96Y
> /tmp/stackage-build2454/prefix-units-0.2.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/prefix-units-0.2.0$ ./Setup register
Registering library for prefix-units-0.2.0..