The build is unreachable.

Build log

> /tmp/stackage-build2456$ stack unpack safe-exceptions-0.1.7.0@sha256:62345cdd953820251904e65c867374cd2aaa5c69b07f7ec8f2fa431d5f202d3a
Unpacked safe-exceptions-0.1.7.0 to /tmp/stackage-build2456/safe-exceptions-0.1.7.0/
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ 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-build2456/safe-exceptions-0.1.7.0$ ./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/safe-exceptions-0.1.7.0 --htmldir=/home/circleci/project/builds/nightly/doc/safe-exceptions-0.1.7.0 --haddockdir=/home/circleci/project/builds/nightly/doc/safe-exceptions-0.1.7.0
Configuring safe-exceptions-0.1.7.0...
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ ./Setup build
Preprocessing library for safe-exceptions-0.1.7.0..
Building library for safe-exceptions-0.1.7.0..
[1 of 1] Compiling Control.Exception.Safe ( src/Control/Exception/Safe.hs, dist/build/Control/Exception/Safe.o )
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181116/safe-exceptions-0.1.7.0-4tAxKhOo5s5IYvMv8sXxJh
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/safe-exceptions-0.1.7.0$ ./Setup register
Registering library for safe-exceptions-0.1.7.0..