The build is unreachable.
Build log
> /tmp/stackage-build2456$ stack unpack pureMD5-2.1.3@sha256:dbd1536b5f78cffffe5bc7f0b51a916beb2253cfea4d9f172b6198cdc9d9d079
Unpacked pureMD5-2.1.3 to /tmp/stackage-build2456/pureMD5-2.1.3/
> /tmp/stackage-build2456/pureMD5-2.1.3$ 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/pureMD5-2.1.3$ ./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/pureMD5-2.1.3 --htmldir=/home/circleci/project/builds/nightly/doc/pureMD5-2.1.3 --haddockdir=/home/circleci/project/builds/nightly/doc/pureMD5-2.1.3
Configuring pureMD5-2.1.3...
> /tmp/stackage-build2456/pureMD5-2.1.3$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/pureMD5-2.1.3$ ./Setup build
Preprocessing library for pureMD5-2.1.3..
Building library for pureMD5-2.1.3..
[1 of 1] Compiling Data.Digest.Pure.MD5 ( Data/Digest/Pure/MD5.hs, dist/build/Data/Digest/Pure/MD5.o )
> /tmp/stackage-build2456/pureMD5-2.1.3$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/pureMD5-2.1.3$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181116/pureMD5-2.1.3-90tt2kIrxFiHw4iRlpGF1q
> /tmp/stackage-build2456/pureMD5-2.1.3$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2456/pureMD5-2.1.3$ ./Setup register
Registering library for pureMD5-2.1.3..