The main config file is [`nix/nix.conf`](/nix/nix.conf) and its main purpose is defining the [binary caches](https://nixos.org/nix/manual/#ch-basic-package-mgmt) which allow download of packages to avoid having to compile them yourself locally.
__NOTE:__ If you are in Asia you might want to add the `https://nix-cache-cn.status.im/` to be first in order of `substituters`. Removing `cache.nixos.org` could also help.
The Nix shell is started in this repo via the [`nix/scripts/shell.sh`](/nix/scripts/shell.sh) script, which is a wrapper around the `nix-shell` command and is intended for use with our main [`Makefile`](/Makefile). This allows for an implicit use of `nix-shell` as the default shell in the `Makefile`.
Normally the shell starts without any specific target platform, if you want to change that you should export the `TARGET` env variable with appropriate value: