[Nix-dev] nixpkgs haskell system got into inconsistent state broken

[Miguel Negrão]

Hi

This week I encountered a situation where when I tried to build one of my
own packages which was working fine before, it would fail claiming that
every single Haskell package it needed was missing:

http://pastebin.com/agqw9dn2
http://pastebin.com/Vyqc5U3e

I had not changed anything or installed anything in nix for quite a while,
the only thing I can think that could have caused this was that my
filesystem had died (btrfs) and I had to restore from backup the whole of /.
I have not used binary cache to build any of the haskell packages, they were
built from source.

Is it possible that the restore of / via rsync could have caused this ?

In the meantime I had did a rm -r /nix and installed everything again and my
system is working again, exactly as before this issue (I had everything
specified in my config.nix), which is a testament to how easy it is to
rebuild a system with nix if you have a declarative description of your
packages.

Thanks,
Miguel