The build is unreachable.

Build log

> /tmp/stackage-build2454$ stack unpack ghc-typelits-knownnat-0.6@sha256:d288c03e68cd9a16c035357e2b6a96ea1bf114ff9b3bfa1b7e3702b921580805
Unpacked ghc-typelits-knownnat-0.6 to /tmp/stackage-build2454/ghc-typelits-knownnat-0.6/
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ 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-build2454/ghc-typelits-knownnat-0.6$ ./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/ghc-typelits-knownnat-0.6 --htmldir=/home/circleci/project/builds/nightly/doc/ghc-typelits-knownnat-0.6 --haddockdir=/home/circleci/project/builds/nightly/doc/ghc-typelits-knownnat-0.6
Configuring ghc-typelits-knownnat-0.6...
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ ./Setup build
Preprocessing library for ghc-typelits-knownnat-0.6..
Building library for ghc-typelits-knownnat-0.6..
[1 of 3] Compiling GHC.TypeLits.KnownNat.Solver ( src/GHC/TypeLits/KnownNat/Solver.hs, dist/build/GHC/TypeLits/KnownNat/Solver.o )
[2 of 3] Compiling GHC.TypeLits.KnownNat.TH ( src/GHC/TypeLits/KnownNat/TH.hs, dist/build/GHC/TypeLits/KnownNat/TH.o )
[3 of 3] Compiling GHC.TypeLits.KnownNat ( src/GHC/TypeLits/KnownNat.hs, dist/build/GHC/TypeLits/KnownNat.o )
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181122/ghc-typelits-knownnat-0.6-4rz2sJ9mM3i2xmllYxURo7
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2454/ghc-typelits-knownnat-0.6$ ./Setup register
Registering library for ghc-typelits-knownnat-0.6..