[Nix-dev] firefox + Nix + sha512

[Sergey Mironov]

Hi. I faced

  error: assertion failed at
/home/grwlf/proj/nixcfg/nixpkgs/pkgs/build-support/fetchurl/default.nix:90:1

when tried to upgrade NixOS from  older release to d541e0d. After
examining the assert condition I decided to upgrade Nix from 1.10 to
nix-1.12pre4591_c879a20.

The error changed from above assert to [error: unknown hash algorithm
‘sha512’]. Looks like only firefox packages are affected (probably,
because other packages still use sha256)

There is a Wiki page

  https://nixos.org/wiki/How_to_update_when_Nix_is_too_old_to_evaluate_Nixpkgs

which contains a link to Hydra report page containing the latest built of Nix.

  https://hydra.nixos.org/job/nixos/trunk-combined/nixpkgs.nix.x86_64-linux/latest-finished

 Unfortunately, all the one-click-install packages are 404.

Could you help me to understand what is happening? Which settings do
people normally use at the moment?

Also, is there a possibility to install new Nix directly from latest nixpkgs?

Regards,
Sergey