The build is unreachable.
Build log
> /tmp/stackage-build2451$ stack unpack tasty-discover-4.2.1@sha256:cd474a555cf524a82a294127588d91e7d93802c5fa276ea08b4f1f2bf6c37180
Unpacked tasty-discover-4.2.1 to /tmp/stackage-build2451/tasty-discover-4.2.1/
> /tmp/stackage-build2451/tasty-discover-4.2.1$ 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/tasty-discover-4.2.1$ ./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/tasty-discover-4.2.1 --htmldir=/home/circleci/project/builds/nightly/doc/tasty-discover-4.2.1 --haddockdir=/home/circleci/project/builds/nightly/doc/tasty-discover-4.2.1
Configuring tasty-discover-4.2.1...
> /tmp/stackage-build2451/tasty-discover-4.2.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/tasty-discover-4.2.1$ ./Setup build
Preprocessing library for tasty-discover-4.2.1..
Building library for tasty-discover-4.2.1..
[1 of 4] Compiling Paths_tasty_discover ( dist/build/autogen/Paths_tasty_discover.hs, dist/build/Paths_tasty_discover.o )
[2 of 4] Compiling Test.Tasty.Config ( library/Test/Tasty/Config.hs, dist/build/Test/Tasty/Config.o )
[3 of 4] Compiling Test.Tasty.Generator ( library/Test/Tasty/Generator.hs, dist/build/Test/Tasty/Generator.o )
[4 of 4] Compiling Test.Tasty.Discover ( library/Test/Tasty/Discover.hs, dist/build/Test/Tasty/Discover.o )
Preprocessing executable 'tasty-discover' for tasty-discover-4.2.1..
Building executable 'tasty-discover' for tasty-discover-4.2.1..
[1 of 2] Compiling Main ( executable/Main.hs, dist/build/tasty-discover/tasty-discover-tmp/Main.o )
[2 of 2] Compiling Paths_tasty_discover ( dist/build/tasty-discover/autogen/Paths_tasty_discover.hs, dist/build/tasty-discover/tasty-discover-tmp/Paths_tasty_discover.o )
Linking dist/build/tasty-discover/tasty-discover ...
> /tmp/stackage-build2451/tasty-discover-4.2.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/tasty-discover-4.2.1$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181121/tasty-discover-4.2.1-Ju6HVIVdPDrICBkvoqhO7o
Installing executable tasty-discover in /home/circleci/project/builds/nightly/bin
> /tmp/stackage-build2451/tasty-discover-4.2.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/tasty-discover-4.2.1$ ./Setup register
Registering library for tasty-discover-4.2.1..