The build is unreachable.

Build log

> /tmp/stackage-build2456$ stack unpack adler32-0.1.2.0@sha256:1a6a55affe1ce5cf61c7d71fa074042d9a5703df1d3322993535e73b908b99fc
Unpacked adler32-0.1.2.0 to /tmp/stackage-build2456/adler32-0.1.2.0/
> /tmp/stackage-build2456/adler32-0.1.2.0$ 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-build2456/adler32-0.1.2.0$ ./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/adler32-0.1.2.0 --htmldir=/home/circleci/project/builds/nightly/doc/adler32-0.1.2.0 --haddockdir=/home/circleci/project/builds/nightly/doc/adler32-0.1.2.0
Configuring adler32-0.1.2.0...
> /tmp/stackage-build2456/adler32-0.1.2.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/adler32-0.1.2.0$ ./Setup build
Preprocessing library for adler32-0.1.2.0..
Building library for adler32-0.1.2.0..
[1 of 1] Compiling Data.Digest.Adler32 ( src/Data/Digest/Adler32.hs, dist/build/Data/Digest/Adler32.o )
> /tmp/stackage-build2456/adler32-0.1.2.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/adler32-0.1.2.0$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181116/adler32-0.1.2.0-BtQ3IZCQK0a5nQEnD5hAbQ
> /tmp/stackage-build2456/adler32-0.1.2.0$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/adler32-0.1.2.0$ ./Setup register
Registering library for adler32-0.1.2.0..