The build is unreachable.

Build log

> /tmp/stackage-build2453$ stack unpack hidden-char-0.1.0.2@sha256:b6fc4301934fbd7c41079c609ebc68a10476a88974f5d2c10cc3b90e4f1213b4
Unpacked hidden-char-0.1.0.2 to /tmp/stackage-build2453/hidden-char-0.1.0.2/
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ 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-build2453/hidden-char-0.1.0.2$ ./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/hidden-char-0.1.0.2 --htmldir=/home/circleci/project/builds/nightly/doc/hidden-char-0.1.0.2 --haddockdir=/home/circleci/project/builds/nightly/doc/hidden-char-0.1.0.2
Configuring hidden-char-0.1.0.2...
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ ./Setup build
Preprocessing library for hidden-char-0.1.0.2..
Building library for hidden-char-0.1.0.2..
[1 of 2] Compiling System.IO.HiddenChar.Posix ( src/System/IO/HiddenChar/Posix.hs, dist/build/System/IO/HiddenChar/Posix.o )
[2 of 2] Compiling System.IO.HiddenChar ( src/System/IO/HiddenChar.hs, dist/build/System/IO/HiddenChar.o )
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181120/hidden-char-0.1.0.2-K3i3ScUJ7jF4VyziYBEvI0
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2453/hidden-char-0.1.0.2$ ./Setup register
Registering library for hidden-char-0.1.0.2..