diff --git a/pkgs/by-name/sw/switch-to-configuration-ng/.envrc b/pkgs/by-name/sw/switch-to-configuration-ng/.envrc
new file mode 100644
index 000000000000..9a9a563f9202
--- /dev/null
+++ b/pkgs/by-name/sw/switch-to-configuration-ng/.envrc
@@ -0,0 +1 @@
+use nix ../../../.. -A switch-to-configuration-ng
diff --git a/pkgs/by-name/sw/switch-to-configuration-ng/README.md b/pkgs/by-name/sw/switch-to-configuration-ng/README.md
index 8230b47c9651..c930d8fce97d 100644
--- a/pkgs/by-name/sw/switch-to-configuration-ng/README.md
+++ b/pkgs/by-name/sw/switch-to-configuration-ng/README.md
@@ -1,3 +1,12 @@
 # switch-to-configuration-ng
 
 This program is a reimplementation of [switch-to-configuration](/nixos/modules/system/activation/switch-to-configuration.pl) in Rust. The goal is to be compatible in as many ways as possible to the original implementation, at least as long as the original is still in nixpkgs. Any behavioral modifications to this program should also be implemented in the original, and vice versa.
+
+## Build in a devshell
+
+```
+cd ./pkgs/by-name/sw/switch-to-configuration-ng
+nix-shell ../../../.. -A switch-to-configuration-ng
+cd ./src
+cargo build
+```