~/vcs/ddns (master) nix-shell
~/vcs/ddns (master) cabal build
Resolving dependencies...
Build profile: -w ghc-8.6.5 -O1
In order, the following will be built (use -v for more details):
 - wreq-0.5.3.2 (lib:wreq) (requires build)
 - ddns-0.0.1 (exe:ddns) (first run)
Starting     wreq-0.5.3.2 (all, legacy fallback)
Building     wreq-0.5.3.2 (all, legacy fallback)

Failed to build wreq-0.5.3.2.
Build log (
/home/patrick/.cabal/logs/ghc-8.6.5/wreq-0.5.3.2-f8a8e1e8c99c3a3eba3629c2ced5bf84a09ac49c066fc64c4e59c0d0c99a0cd8.log
):
[1 of 1] Compiling Main             ( /home/patrick/vcs/ddns/dist-newstyle/tmp/src-29003/wreq-0.5.3.2/dist/setup/setup.hs, /home/patrick/vcs/ddns/dist-newstyle/tmp/src-29003/wreq-0.5.3.2/dist/setup/Main.o )
Linking /home/patrick/vcs/ddns/dist-newstyle/tmp/src-29003/wreq-0.5.3.2/dist/setup/setup ...
Configuring wreq-0.5.3.2...
Preprocessing library for wreq-0.5.3.2..
Building library for wreq-0.5.3.2..
[ 1 of 15] Compiling Network.Wreq.Cache.Store ( Network/Wreq/Cache/Store.hs, dist/build/Network/Wreq/Cache/Store.o )
[ 2 of 15] Compiling Network.Wreq.Internal.OAuth1 ( Network/Wreq/Internal/OAuth1.hs, dist/build/Network/Wreq/Internal/OAuth1.o )
[ 3 of 15] Compiling Network.Wreq.Internal.Types ( Network/Wreq/Internal/Types.hs, dist/build/Network/Wreq/Internal/Types.o )
[ 4 of 15] Compiling Network.Wreq.Lens.Machinery ( Network/Wreq/Lens/Machinery.hs, dist/build/Network/Wreq/Lens/Machinery.o )
[ 5 of 15] Compiling Network.Wreq.Internal.Lens ( Network/Wreq/Internal/Lens.hs, dist/build/Network/Wreq/Internal/Lens.o )
<command line>: can't load .so/.DLL for: libz.so (libz.so: cannot open shared object file: No such file or directory)
cabal: Failed to build wreq-0.5.3.2 (which is required by exe:ddns from
ddns-0.0.1). See the build log above for details.