i always seem to get this wrong Change-Id: Ib6f31523aba1d9f9a32d9af95b96b8d75e0ec16e Reviewed-on: https://cl.tvl.fyi/c/depot/+/6863 Reviewed-by: wpcarro <wpcarro@gmail.com> Autosubmit: wpcarro <wpcarro@gmail.com> Tested-by: BuildkiteCI
1.6 KiB
Background
I rarely use nix-shell
for its originally intended purpose of "reproducing the
environment of a derivation for development". Instead, I often use it to put
some executable on my PATH
for some ad hoc task.
What's nix-shell
's "intended purpose"? Let's ask The Man (man nix-shell
):
The command nix-shell will build the dependencies of the specified derivation, but not the derivation itself. It will then start an interactive shell in which all environment variables defined by the derivation path have been set to their corresponding values, and the script $stdenv/setup has been sourced. This is useful for reproducing the environment of a derivation for development.
Because I'm abusing nix-shell
in this way, I'm liable to forget that
nix-shell
puts buildInputs
on PATH
and not the derivation itself. But I
often only want the derivation!
Solution
Pass the Nix expression to nix-shell -p
:
λ nix-shell -p '(import /depot {}).tvix.eval'
Explanation
This works because Nix forwards the arguments passed to -p
(i.e. --packages
)
and interpolates them into this expression here: source
{ ... }@args:
with import <nixpkgs> args;
(pkgs.runCommandCC or pkgs.runCommand) "shell" {
buildInputs = [
# --packages go here
];
}
So really you can pass-in any valid Nix expression that produces a derivation
and nix-shell
will put its outputs on your PATH
.
Enjoy!