The build is unreachable.

Build log

> /tmp/stackage-build2451$ stack unpack constraints-0.10.1@sha256:25190a3401d9371179abc3144ea087148976ebeafdd1b3945bd8a0f799951cb8
Unpacked constraints-0.10.1 to /tmp/stackage-build2451/constraints-0.10.1/
> /tmp/stackage-build2451/constraints-0.10.1$ 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/constraints-0.10.1$ ./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/constraints-0.10.1 --htmldir=/home/circleci/project/builds/nightly/doc/constraints-0.10.1 --haddockdir=/home/circleci/project/builds/nightly/doc/constraints-0.10.1
Configuring constraints-0.10.1...
> /tmp/stackage-build2451/constraints-0.10.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/constraints-0.10.1$ ./Setup build
Preprocessing library for constraints-0.10.1..
Building library for constraints-0.10.1..
[1 of 7] Compiling Data.Constraint  ( src/Data/Constraint.hs, dist/build/Data/Constraint.o )
[2 of 7] Compiling Data.Constraint.Deferrable ( src/Data/Constraint/Deferrable.hs, dist/build/Data/Constraint/Deferrable.o )
[3 of 7] Compiling Data.Constraint.Forall ( src/Data/Constraint/Forall.hs, dist/build/Data/Constraint/Forall.o )
[4 of 7] Compiling Data.Constraint.Lifting ( src/Data/Constraint/Lifting.hs, dist/build/Data/Constraint/Lifting.o )
[5 of 7] Compiling Data.Constraint.Nat ( src/Data/Constraint/Nat.hs, dist/build/Data/Constraint/Nat.o )
[6 of 7] Compiling Data.Constraint.Symbol ( src/Data/Constraint/Symbol.hs, dist/build/Data/Constraint/Symbol.o )
[7 of 7] Compiling Data.Constraint.Unsafe ( src/Data/Constraint/Unsafe.hs, dist/build/Data/Constraint/Unsafe.o )
> /tmp/stackage-build2451/constraints-0.10.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/constraints-0.10.1$ ./Setup copy
Installing library in /home/circleci/project/builds/nightly/lib/x86_64-linux-ghc-8.7.20181121/constraints-0.10.1-LihCf6sTmWo3PuKd4WAL8L
> /tmp/stackage-build2451/constraints-0.10.1$ ghc -clear-package-db -global-package-db -package-db=/home/circleci/project/builds/nightly/pkgdb Setup
> /tmp/stackage-build2451/constraints-0.10.1$ ./Setup register
Registering library for constraints-0.10.1..