Weird nix commands and shell inputs

Some stuff I have needed using NixOS but had a hard time finding documentation for.

Aspell with specific directory 

nix-shell -p 'aspellWithDicts(dict: [ dict.en ])'

Build standalone package 

nix-build -E 'with import <nixpkgs> {}; callPackage ./default.nix {}'

Get current NixOS nixpkgs revision 

nix-instantiate --eval '<nixpkgs>' --attr lib.version

Roll back channel 

# go back one version
nix-channel --rollback

# go back to specific version
nix-channel --rollback <revision>
^ back to top