From 6032eb03d55fed4f062365169f4734ca2994cbda Mon Sep 17 00:00:00 2001
From: Tom Prince <tom.prince@private.storage>
Date: Mon, 13 Sep 2021 18:33:02 -0600
Subject: [PATCH] Avoid copying nixpkgs to the store a second time in
nix-shell.
---
shell.nix | 11 ++++++++++-
1 file changed, 10 insertions(+), 1 deletion(-)
diff --git a/shell.nix b/shell.nix
index ce1add06..fe76c1e7 100644
--- a/shell.nix
+++ b/shell.nix
@@ -3,8 +3,17 @@ let
in
{ pkgs ? release2105 }:
pkgs.mkShell {
+ # When a path (such as `pkgs.path`) is interpolated into a string then nix
+ # first adds that path to the store, and then interpolates the store path
+ # into the string. We use `builtins.toString` to convert the path to a
+ # string without copying it to the store before interpolating. Either the
+ # path is already in the store (e.g. when `pkgs` is `release2105`) so we
+ # avoid making a second copy with a longer name, or the user passed in local
+ # path (e.g. a checkout of nixpkgs) and we point at it directly, rather than
+ # a snapshot of it.
+ # See https://github.com/NixOS/nix/issues/200 and https://github.com/NixOS/nix/issues/1728
shellHook = ''
- export NIX_PATH="nixpkgs=${pkgs.path}";
+ export NIX_PATH="nixpkgs=${builtins.toString pkgs.path}";
'';
buildInputs = [
pkgs.morph
--
GitLab