nix print-dev-env: Add --json flag

1 files changed, 34 insertions, 3 deletions

diff --git a/src/nix/print-dev-env.md b/src/nix/print-dev-env.md
index b80252acf..2aad491de 100644
--- a/src/nix/print-dev-env.md
+++ b/src/nix/print-dev-env.md
@@ -8,12 +8,43 @@ R""(
   # . <(nix print-dev-env nixpkgs#hello)
   ```
 
+* Get the build environment in JSON format:
+
+  ```console
+  # nix print-dev-env nixpkgs#hello --json
+  ```
+
+  The output will look like this:
+
+  ```json
+  {
+    "bashFunctions": {
+      "buildPhase": " \n    runHook preBuild;\n...",
+      ...
+    },
+    "variables": {
+      "src": {
+        "type": "exported",
+        "value": "/nix/store/3x7dwzq014bblazs7kq20p9hyzz0qh8g-hello-2.10.tar.gz"
+      },
+      "postUnpackHooks": {
+        "type": "array",
+        "value": ["_updateSourceDateEpochFromSourceRoot"]
+      },
+      ...
+    }
+  }
+  ```
+
 # Description
 
-This command prints a shell script that can be sourced by `b`ash and
-that sets the environment variables and shell functions defined by the
-build process of *installable*. This allows you to get a similar build
+This command prints a shell script that can be sourced by `bash` and
+that sets the variables and shell functions defined by the build
+process of *installable*. This allows you to get a similar build
 environment in your current shell rather than in a subshell (as with
 `nix develop`).
 
+With `--json`, the output is a JSON serialisation of the variables and
+functions defined by the build process.
+
 )""