The build is unreachable.

Build log

> /tmp/stackage-build2452$ stack unpack retry-0.7.7.0@sha256:7b00ea9a64adec514a830209ae3d75919d5b510eb688783634f61469b4d3d182
Unpacked retry-0.7.7.0 to /tmp/stackage-build2452/retry-0.7.7.0/
> /tmp/stackage-build2452/retry-0.7.7.0$ 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-build2452/retry-0.7.7.0$ ./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/retry-0.7.7.0 --htmldir=/home/circleci/project/builds/nightly/doc/retry-0.7.7.0 --haddockdir=/home/circleci/project/builds/nightly/doc/retry-0.7.7.0
Configuring retry-0.7.7.0...
> /tmp/stackage-build2452/retry-0.7.7.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2452/retry-0.7.7.0$ ./Setup build
Preprocessing library for retry-0.7.7.0..
Building library for retry-0.7.7.0..
[1 of 1] Compiling Control.Retry    ( src/Control/Retry.hs, dist/build/Control/Retry.o )
> /tmp/stackage-build2452/retry-0.7.7.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2452/retry-0.7.7.0$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181119/retry-0.7.7.0-1oiL4IpurlUIvkyYitN1pX
> /tmp/stackage-build2452/retry-0.7.7.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2452/retry-0.7.7.0$ ./Setup register
Registering library for retry-0.7.7.0..