environment.shellAliases not honored for ls

[mfiano]

Issue description

Defining a shell alias using config.environment.shellAliases for the ls command is not honored, due to this being defined afterwards:

nixpkgs/nixos/modules/programs/shell.nix

Lines 17 to 21 in 56904d7

	environment.shellAliases =
	{ ls = "ls --color=tty";
	ll = "ls -l";
	l = "ls -alh";
	};

Steps to reproduce

Try overriding config.environment.shellAliases = { ls = "..." };

Technical details

• system: "x86_64-linux"
• host os: Linux 4.9.84, NixOS, 18.03pre130151.268d99b1fe4 (Impala)
• multi-user?: yes
• sandbox: yes
• version: nix-env (Nix) 1.11.16
• channels(root): "nixos-18.03pre130151.268d99b1fe4"
• channels(mfiano): "nixos-17.09-17.09.3101.fd1d76bb1a8"
• nixpkgs: /nix/var/nix/profiles/per-user/root/channels/nixos/nixpkgs

[yesbox]

Are you sure? I have the following working as expected on nixos-17.09 and nixos-unstable with bash and zsh.

config.environment.shellAliases = { ls = "ls --color=tty -F" };

[mfiano]

Yes, I'm sure. I have a pile of aliases defined in config.environment.shellAliases, and ls is the only one that is not correct -- it's exactly what is defined in the above link.

[teto]

If you use zsh, then environment.shellAliases is not used, you have to add it yourself which is counterintuitive IMO.

[mfiano]

This is bash, and all of my environment.shellAliases are being used except the one for ls is instead aliased to be that of the above link in the nixpkgs source.

[danbst]

That's because shellAliases are defined as attrs

nixpkgs/nixos/modules/programs/bash/bash.nix

Line 64 in 7e40287

type = types.attrs; # types.attrsOf types.stringOrPath;

And merge function for attrs type replaces configuration attributes with default:

nixpkgs/lib/types.nix

Line 149 in 7e40287

merge = loc: foldl' (res: def: mergeAttrs res def.value) {};

Merge function should work the other way round - replace default values with configuration

[infinisil]

Solved with #44441