[Nix-dev] nix suddenly unusable as of version upgrade

[Eelco Dolstra]

Hi,

Bill Trost wrote:

> Yesterday I did an update from the nixpkgs-unstable channel and at some
> point during the upgrade process is automatically upgraded to schema
> version six. I thought that was fine, but now when I try to run nix-env or
> nix-channel, I get the error message
> 
>   error: current Nix store schema is version 6, but I only support 5
> 
> Uh, now what? How do I recover from this situation?

Doh!  Nixpkgs contains an experimental branch of Nix (nixSqlite) which should
not be installed, but is because it has a higher version number.  That's where
the new schema comes from.  I've now marked it as "low priority" to prevent it
from being installed if you do "nix-env -u nix".

To revert to the old Nix store schema, do:

$ echo -n 5 > /nix/var/nix/db/schema

-- 
Eelco Dolstra | http://www.st.ewi.tudelft.nl/~dolstra/