diff --git a/README.md b/README.md
index ec5be24..0b0a84a 100644
--- a/README.md
+++ b/README.md
@@ -11,8 +11,23 @@ Install Nix with flakes.
 nix build
 ```
 
-Or run without installing:
+Or run directly:
 
 ```sh
 nix run "git+https://code.youwen.dev/youwen5/cartographer.git"
 ```
+
+You may also be able to compile it manually using `cargo` but this is not
+officially supported. Use the latest stable Rust toolchain. You must have
+`openssl` and the necessary libraries for Rust to link against.
+
+## Hacking
+
+You can enter a development shell with all of the required dependencies
+(including `openssl`) with
+
+```bash
+nix develop
+```
+
+Or use [direnv](https://direnv.net/) and simply `direnv allow`.