ocamlPackages.csv-1.7 in nixos-17.09 cannot be installed due to a deprecated source URL.
I could not find a valid download URL for 1.7, but 2.0 (which is in unstable) works fine.
Should this be bumped?

Steps to reproduce

nix-shell -p ocamlPackages.csv -I nixpkgs=https://github.com/NixOS/nixpkgs-channels/archive/nixos-17.09.tar.gz

[...]
trying https://math.umons.ac.be/anum/software/csv/csv-1.7.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
curl: (22) The requested URL returned error: 404 Not Found
[...]