The build is unreachable.

Build log

> /tmp/stackage-build2454$ stack unpack errors-ext-0.4.2@sha256:165c160eaec89930a89c92f07fcdc5dd859c24094caaa4486e4ec1c328be0348
Unpacked errors-ext-0.4.2 to /tmp/stackage-build2454/errors-ext-0.4.2/
> /tmp/stackage-build2454/errors-ext-0.4.2$ 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/errors-ext-0.4.2$ ./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/errors-ext-0.4.2 --htmldir=/home/circleci/project/builds/nightly/doc/errors-ext-0.4.2 --haddockdir=/home/circleci/project/builds/nightly/doc/errors-ext-0.4.2
Configuring errors-ext-0.4.2...
> /tmp/stackage-build2454/errors-ext-0.4.2$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/errors-ext-0.4.2$ ./Setup build
Preprocessing library for errors-ext-0.4.2..
Building library for errors-ext-0.4.2..
[1 of 2] Compiling Control.Error.Extensions ( src/Control/Error/Extensions.hs, dist/build/Control/Error/Extensions.o )
[2 of 2] Compiling Paths_errors_ext ( dist/build/autogen/Paths_errors_ext.hs, dist/build/Paths_errors_ext.o )
> /tmp/stackage-build2454/errors-ext-0.4.2$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/errors-ext-0.4.2$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181122/errors-ext-0.4.2-IYODW73WehRKllDU6TWeSV
> /tmp/stackage-build2454/errors-ext-0.4.2$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/errors-ext-0.4.2$ ./Setup register
Registering library for errors-ext-0.4.2..