building '/nix/store/cqjb6qqajbysi905z6p0j4y5npvw13va-lens-4.15.tar.gz.drv'... trying http://hackage.haskell.org/package/lens-4.15.tar.gz % Total % Received % Xferd Average Speed Time Time Time Current Dload Upload Total Spent Left Speed 0 0 0 0 0 0 0 0 --:--:-- --:--:-- --:--:-- 0 100 951k 100 951k 0 0 1394k 0 --:--:-- --:--:-- --:--:-- 15.4M copying path '/nix/store/i6hwjzc9368m2rqm04qikwn04s6180yz-test-framework-th-0.2.4' from 'https://cache.nixos.org'... building '/nix/store/680d0xz6gh6j2pwbs4hf4mvpkk7zm7gc-lens-4.15.drv'... setupCompilerEnvironmentPhase Build with /nix/store/3cv3s9lv79qjkqyafbclbk03gz5z813w-ghc-8.2.2. ignoring (possibly broken) abi-depends field for packages unpacking sources unpacking source archive /nix/store/s13lpzypbbzfc2cd59i7qhcn3nc20q3s-lens-4.15.tar.gz source root is lens-4.15 setting SOURCE_DATE_EPOCH to timestamp 1475992011 of file lens-4.15/.vim.custom patching sources compileBuildDriverPhase setupCompileFlags: -package-db=/tmp/nix-build-lens-4.15.drv-0/package.conf.d -j12 -threaded [1 of 1] Compiling Main ( Setup.lhs, /tmp/nix-build-lens-4.15.drv-0/Main.o ) Setup.lhs:8:31: error: Module ‘Distribution.Package’ does not export ‘PackageName(PackageName)’ | 8 | import Distribution.Package ( PackageName(PackageName), Package, PackageId, InstalledPackageId, packageVersion, packageName ) | ^^^^^^^^^^^^^^^^^^^^^^^^ builder for '/nix/store/680d0xz6gh6j2pwbs4hf4mvpkk7zm7gc-lens-4.15.drv' failed with exit code 1 cannot build derivation '/nix/store/6mpb1bvcbyxzbbx98gqwc7xggf23pm33-snap-test-0.1.drv': 1 dependencies couldn't be built