nix dev-shell: Use 'provides.devShell' by default

Thus

  $ nix dev-shell

will now build the 'provides.devShell' attribute from the flake in the
current directory. If it doesn't exist, it falls back to
'provides.defaultPackage'.

1 files changed, 4 insertions, 2 deletions

diff --git a/shell.nix b/shell.nix
index 8167f87a2..d7e63bad3 100644
--- a/shell.nix
+++ b/shell.nix
@@ -1,6 +1,8 @@
-{ useClang ? false }:
+{ useClang ? false
+, nixpkgs ? builtins.fetchTarball https://github.com/NixOS/nixpkgs-channels/archive/nixos-19.03.tar.gz
+}:
 
-with import (builtins.fetchTarball https://github.com/NixOS/nixpkgs-channels/archive/nixos-19.03.tar.gz) {};
+with import nixpkgs { system = builtins.currentSystem or "x86_64-linux"; };
 
 with import ./release-common.nix { inherit pkgs; };