The build is unreachable.
Build log
> /tmp/stackage-build2455$ stack unpack iso8601-time-0.1.5@sha256:4b690a86f4948557c802b5298e07d9076ef4ea7142baaad20c9847a9030a8c40
Unpacked iso8601-time-0.1.5 to /tmp/stackage-build2455/iso8601-time-0.1.5/
> /tmp/stackage-build2455/iso8601-time-0.1.5$ 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-build2455/iso8601-time-0.1.5$ ./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/iso8601-time-0.1.5 --htmldir=/home/circleci/project/builds/nightly/doc/iso8601-time-0.1.5 --haddockdir=/home/circleci/project/builds/nightly/doc/iso8601-time-0.1.5
Configuring iso8601-time-0.1.5...
> /tmp/stackage-build2455/iso8601-time-0.1.5$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2455/iso8601-time-0.1.5$ ./Setup build
Preprocessing library for iso8601-time-0.1.5..
Building library for iso8601-time-0.1.5..
[1 of 1] Compiling Data.Time.ISO8601 ( src/Data/Time/ISO8601.hs, dist/build/Data/Time/ISO8601.o )
> /tmp/stackage-build2455/iso8601-time-0.1.5$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2455/iso8601-time-0.1.5$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181122/iso8601-time-0.1.5-2S3auB1R9afAqfVs80Xt5R
> /tmp/stackage-build2455/iso8601-time-0.1.5$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2455/iso8601-time-0.1.5$ ./Setup register
Registering library for iso8601-time-0.1.5..