The build is unreachable.

Build log

> /tmp/stackage-build2451$ stack unpack elf-0.29@sha256:24f8b6e1cd56e9a6a766ac8e453f2856f9ed9bfee5769a3e42fa723c599f5cfd
Unpacked elf-0.29 to /tmp/stackage-build2451/elf-0.29/
> /tmp/stackage-build2451/elf-0.29$ 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-build2451/elf-0.29$ ./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/elf-0.29 --htmldir=/home/circleci/project/builds/nightly/doc/elf-0.29 --haddockdir=/home/circleci/project/builds/nightly/doc/elf-0.29
Configuring elf-0.29...
> /tmp/stackage-build2451/elf-0.29$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/elf-0.29$ ./Setup build
Preprocessing library for elf-0.29..
Building library for elf-0.29..
[1 of 1] Compiling Data.Elf         ( src/Data/Elf.hs, dist/build/Data/Elf.o )
> /tmp/stackage-build2451/elf-0.29$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/elf-0.29$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181119/elf-0.29-IMlIgSkQcc0GjOmyjqTBgh
> /tmp/stackage-build2451/elf-0.29$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/elf-0.29$ ./Setup register
Registering library for elf-0.29..